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PHP Reference: Beginner to Intermediate PHP5

PHP Reference: Beginner toIntermediate PHP5

Mario Lurig

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PHP Reference:

Beginner to Intermediate PHP5

ISBN: 978-1-4357-1590-5

Creative Commons Attribution-NonCommercial-SareAli!e "#0

You are free:

to Share to copy, distribute and transmit the work to Remix

to adapt the work Under the following conditions:

Attribution. You must attribute the work in the manner specified by the author orlicensor (but not in any way that suggests that they endorse you or your use of the

work).

Noncommercial. You may not use this work for commercial purposes.

Share Alike. If you alter, transform, or build upon this work, you may distribute theresulting work only under the same or similar license to this one.

For any reuse or distribution, you must make clear to others the license terms of thiswork.

Any of the above conditions can be waived if you get permission from the copyright

holder. Nothing in this license impairs or restricts the author's moral rights.FIRST

EDITION

http ://www. phpreferencebook. com

Cover art credit (PHP REFERENCE:), included wit !ermi""ion:

Leo Reynolds (www.flickr.com/lwr/) - 7 images Patrick Goor (

www.labworks.eu) - 3 images Eva the Weaver (

www.flickr.com/evaekeblad/) - 2 images Duncan Cumming (

www.flickr.com/duncan/) - 1 image

2
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Contents

Preface . . . . . . . 5

Miscellaneous Things You Should Know . . . 9

Operators . . . . . . . 19

Control Structures . . . . . . 25

Global Variables . . . . . . 33

Variable Functions . . . . . . 35

String Functions . . . . . . 41

Array Functions . . . . . . 71

Date/Time Functions . . . . . . 103

Mathematical Functions . . . . . 111

MySQL Functions . . . . . . 115

Directory & File System Functions . . . . 127

Output Control (Output Buffer) . . . . 139

Sessions . . . . . . . 145

Regular Expressions . . . . . . 149

Common Language Index . . . . . 159

Function Index. . . . . . . 161

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Mario Lurig

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Preface

I taught myself PHP and MySQL and found myself, at times, without

internet access and thus without search access to thePHP.netmanual (

http://www.php.net/manual/en/). Since coding was not my primary job, I needed

a refresher on syntax, usage, and most of all, a reminder of how to code PHP without

spending an hour debugging a silly mistake. I printed out reference sheets, cards,

cheat sheets and tried to work off of them exclusively. However, I still found myself

needing more than would fit on one page of 8.5" x 11" paper front and back. So, off I

went to the web and the local bookstore. After spending some time with a few books,giving them a trial run, I ran into two major problems:

1. I spent most of the time weeding through extensive tutorials to find the

keyword and answer I was looking for, sometimes fruitlessly.

2. Information was biased or surrounded by irrelevant and often confusing

code that did little to explain thewhatof the function.

I figured I couldn't be the only one with this problem, and quickly found out

that I wasn't alone thanks to a chance run-in at a local bookstore. Casual PHP

programmers, sometimes away from the internet, wanting a quick reference book

that assumes they have some experience with PHP and understood the basics while

still needing a little clarification sometimes on the details. Therefore, this book wasborn.

For this edition, I decided to eliminate some of the more advanced aspects of

PHP programming: object oriented programming, image manipulation/creation,

secondary modules, and a few others. Secondarily, items such as mail handling, file

manipulation, regular expressions, MySQL, sessions, and cookies were balanced for

complexity and usability, usually excluding the more advanced uses, such as

streams . Finally, this book is not an exhaustive collection of every PHP function, but a

majority selection of those appropriate for beginner to intermediate programmers.

The most common or effective functions are included and some aliases are left out to

reduce confusion, such as includingis_int()and notis_long().

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A few bits of nomenclature should be addressed and provided, to better

understand the word/code used inside this book. In other words, here are some

assumptions made inside this book that you should understand:

expr- An expression(e.g.$x == 1), includingboolean

$variable - A string, integer, float, arrayorboolean1

$scalar - Astring, integer, float,orboolean

$string - Astringvariable or its equivalent (e.g."string" or 'string' ) $array - Anarray

variable or its equivalent (e.g.array( 'one' , 'two' , 'three' ) )key- Represents the key

(integerorstring)of anarray(e.g.$array[key] )value- In relation to anarray,

represents the$variablevalue (e.g.array('value') )

This book also shows all code using procedural PHP and standard syntax.

However, you will find many tips will include the alternative syntax for control

structures as to better allow you, the reader, to choose whichever you would prefer.

Here is an example of both:

// Standard syntax if

($x == 1) {

echo 'Hello World!'; }

else {

echo 'Goodye World!';

}

// lternati"e syntax if

($x == 1) #echo 'Hello World!';

else#

echo 'Goodye World!';

endif;

Furthermore, the use of whitespace and indenting is for clarity and is completely up

to your preference. Styles vary greatly in the community, so please be aware that the

use of spaces or whitespace does not directly affect

the PHP code.

The majority of the book is a collection of functions, their descriptions,

example code, maybe an extra tip, and some related functions that may be of interest.

All sample code will be accompanied by the sample output, and the output will have

a gray background. Thedefinitionandexamplesection is separated from the

extraneoustipsection by the use of three black clovers, centered on the line. It is

meant as a simple visual clue to keep one from getting distracted or lost and

confusing the next bit of information as required reading. All functions will be

presented using the following formatting:

$

1 Boolean is usuall% use& 'itin an e()ression# *ile it is also evaluate& as a variable+ out)utresults ma% var% an& are note& 'itin s)eci,ic ,unctions 'enever )ossible


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function name(input, [optional input])

Description/definition

Example:

ode %ith // co&&ents

tt of code as seen thro*h a %e ro%ser's ott

See Also:

function -simplified and relevant definition

function -simplified and relevant definition

. . .

Optional Section}Tip to help with usage or trick on using it

+xtra code related tothe ti

tt

,-. = f

,1. = ode}

Thanks, and enjoy the show!

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Mario Lurig

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Miscellaneous Things You Should Know

Not everything fits into a neat little category, nor does everything in PHP

belong in this reference book. However, sometimes they deserve a quick note and a

little attention and shall be included here.

PHP CodeFor portability and compatibility, always use the long form. Long

form:0h exr

Short form:0 expr

Short form equivalent of Note:

No closing semicolon (;) is required.0= exr

Semicolon ( ; )

All statements must end in a semicolon ( ; )! Otherwise, errors will be generated. If

the error doesn't make sense, you probably are missing a semicolon somewhere!

Quotations

' ' (single quotes) - Content inside single quotes is evaluated literally. Therefore,

$string actually means: (dollar sign)string, and does not represent the variable's value.

Example:

$strin* = 'Sin*le 2otes';

echo '$strin* ' ;

$strin*

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" " (double quotes) - Variables inside double quotes are evaluated for their values.

Example:

$strin* = '3ole 2otes';

echo 4$strin*4;

3ole 2otes

Backslash (Escape Character)

Escapes characters that should be evaluated literally when inside double

quotations.

Example:

$strin* = '3ole 2otes';

echo 45$strin* is set as $strin*4;

$strin* is set as 3ole 2otes

Special Characters

backslash ( \ )

question mark ( ? )

single ( ' ) quotes

double ( " ) quotes

dollar sign ( $ )

Example:

$strin* = 'Hello World!';

echo 46he "ariale 5$strin* contains 5' $strin* 5' 54 554; 6he "ariale

$strin* contains 5' Hello World! 5' 4 5 echo '6he "ariale 5$strin*

contains 5' $strin* 5' 54 55'; 6he "ariale 5$strin* contains ' $strin*

' 54 5

Comments

Single line, for everything to the right of the doubleforwardslashes:// 6his is a co&&ent

Multiple lines, opening and closing tags: /* *//7 6his is a

co&&ent 7/

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Formatting Characters

5n - New line

5r - Carriage return

5t - Tab

5 - Backspace

define(name,value[, $boolean])

name-$string

value-$scalar

$boolean- [optional]default:FALSE, case-sensitive

Define a constant, a set value that is assigned globally, making it available to

functions and classes without passing them directly as an argument.

Examples:

define('H+88'9 'Hello World!');echo H+88;

Hello World!

define('G:++6


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if (-==-){

fnction hello(){ echo 'Hello ';

}

}hello();

there();

fnction there()

{ echo 'there';

}

Hello there

Functions can have no arguments (as above), arguments passed to them, or default

arguments with passed arguments as optional. The argument names are used

within that function as variable names.

fnction ar*s($a9 $){

// Has no defalt "ales9 re>ires t%o ints echo 4a= $a9 = $4;

}ar*s(19?); a =19 = ?

Some examples using the following function:

fnction ar*s($a = 19 $ = ?){ //

Has defalt "ales set $c = $a @

$;

echo 4a = $a9 = $9 a@ = $c4;

}

ar*s();

a = 19 = ?9 a@ = A

ar*s (B9B);

a = B9 = B9 a@ = 1-

ar*s(1-);

a = 1-9 = ?9 a@ = 1?

ar*s($3oes


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If multiple pages will refer to the same functions, create a separate

functions.phpfile (name it whatever you like) andrequire()or

require_once()with pages that will need to use those functions. For speed

and file size, page specific functions should be included directly on the

necessary page.____________________________________________________________

exit([$string])

die([$string])

Stops the current script and outputs the optional$string.

Example:

$reslt = C&ys>lDconnect('d'9 'ser'9 '%')or die('nale to connect to dataase!'); echo

'f it fails9 this %ill ne"er e seen';

nale to connect to dataase!

Note:The above output would only display if it failed. If the @ was not present before

mysql_connect(), PHP would output a warning as well.

eval($string)

Evaluates a string as if it was code. This can be used to store code in a database and

have it processed dynamically by PHP as if it were part of the page. All appropriate

aspects of code must be included, such as escaping items with a backslash (\) and

including a semicolon (;) at the end of the string.

Example:

$na&e = 'Eario';

$strin* = 'Ey na&e is $na&eF'; // otes echo

$strin*;

$code = 45$e"alstrin* = 54 $strin* 54 ;4;

// +ffect of acslash escae# $code = 4$e"alstrin* = 4 $strin* 4 ;4;

e"al($code); // e"al($e"alstrin* = 4 Ey na&e is $na&e 4 ;); // $e"alstrin* is

the sa&e as $strin*9 excet %ith dole >otes no% echo $e"alstrin*;

Ey na&e is $na&eF Ey na&e is EarioF

sleep($integer)

Pauses PHP for$integeramount of seconds before continuing.

Example:

slee(?); // ase for ? seconds

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usleep($integer)

Pauses PHP for$integeramount of microseconds before continuing.

Example:

slee(1------); // ase for 1 second

uniqid([$scalar [,entropy]])

entropy- [optional]$booleandefault:FALSE, 13 character output

Generate a unique ID based on the$scalar.If no input is given, the current time in

microseconds is used automatically. This is best used in combination with other

functions to generate a more unique value. If the$scalaris an empty string ('') and

entropyis set to TRUE, a 26 character output is provided instead of a 13 character

output.

Examples:

$id = ni>id();

echo $id;

IccJ?cK1IcKK

$rando&Did = ni>id(&tDrand());

echo $rando&Did;

LA KBI ?B K1 IccJ?cK1Icd

$&dB = &dB($rando&Did);

echo $&dB;

eaBI Aadcdf? -?1BA K1J?c?dfA JB1f

See Also:

md5() -MD5 algorithm based encryption

setcookie(name[,value][,time][,path][,domain][,secure][,httponly])

name-$string

value- [optional]$string

time- [optional]$integerdefault:till the end of the sessionpath-

[optional]$stringdefault:current directorydomain- [optional]

$stringdefault:current domain(e.g.

http ://www.example.com)secure- [optional]$booleandefault:FALSE,

does not require a secure

connection

httponly- [optional]$booleandefault:FALSE, available to scripting languages

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Sets a cookie2, visible to the server on the next page load. To send then default value,

use a set of single quotes ('') for each argument you want to skip except thetime

argument, which should use0to send thedefaultvalue. In most cases, providing the

name, value, time,anddomainwill cover most uses (with '' for path).

Examples:

setcooie('ooie'9'Set till end of this session'9-);

// 6his %ill dislay roerly after the a*e has een reloaded

rintDr($DM+);

rray ( ,ooie. = Set till end of this session )setcooie('ooie'9'Set for L- seconds for all sdo&ains of exa&leFco&9 sch

as %%%F9 &ailF9 etcF'9ti&e()@L-99999Fexa&leFco&');

rintDr($DM+);

rray ( ,ooie. = Set for L- seconds for all sdo&ains of exa&leFco&9

sch as %%%F9 &ailF9 etcF )

Some common times used for expiration: time()

+60*60*24 is equal to 1 day time()+60*60*24*30 is

equal to 30 days

time()-1 is one second in the past, used toexpire/deletea cookiesetcooie ( ' ooie ' '9ti&e()N1) ;

// exires the ooie na&ed 'ooie'F


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et_magic_quotes_gpc()

Returns0if it is off,1otherwise.

Used to determine if magic quotes is on. This check is used for code portability and

determining if the addition of backslashes is necessary for security purposes and

preventing SQL injection. Magic_quotes_gpc processes GET/POST/Cookie data

and, if turned on, automatically processes the above data every time with

addslashes().

Example:

if (*etD&a*icD>otesD*c()){

echo 'Ea*ic 2otes is on!'; }

else{

echo 'Ea*ic 2otes is


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mail(to, subject, message [, headers] [, parameters])

to-$string

subject-$string

message-$string

headers- [optional]$string

parameters- [optional]$string

This uses the sendmail binary which may not be configured or available depending

on your system/setup.This is included here for basic reference. The configuration and

security concerns are outside of the scope of this book.Security consideration:

http://www.securephpwiki.com/index.php/Email_Injection

Example:

$to = 'RohndoeCexa&leFco&';

$sRect = 'Hello'; $&essa*e =

'Hi ohn 3oe';

$headers = 'Pro RanedoeCexa&leFco&' F 45r5n4 F

':elyN6o# RanedoeCexa&leFco&' F 45r5n4 F

'TNEailer# QHQ/' F h"ersion();

&ail($to9 $sRect9 $&essa*e9 $headers);

exec(command[,output][,return])

command-$stringto execute the external program

output- [optional] Variable name to assign all the output of thecommandas an array

return- [optional] Variable name to assign the return status as an$integer.Works

only whenoutputis also present.

The function will return the last line of the executed program's output. If the program

fails to run and bothoutputandreturnare both present,returnwill be most commonly

set to 0 when successfully executed and 127 when thecommandfails.

Example (Linux specific program):

$lastline = exec('cal'9 $ott9 $retrn);

echo '0re'; // Por etter for&attin* of rintDr()

rintDr($ott);

"arDd&($lastline9 $retrn);

rray ,-. = Earch ?--J,1. = S Eo 6 We 6h Pr Sa

,?. = 1,A. = ? A B L I J

,. = K 1- 11 1? 1A 1 1B,B. = 1L 1I 1J 1K ?- ?1 ??,L. = ?A ? ?B ?L ?I ?J ?K,I. = A- A1

)strin*(B) 4A- A14int (-)

|header($string [,replace_flag][,http_response_code])

replace_flag- [optional]$booleandefault:TRUE, replace similar header

http_response_code- [optional]$integer

Sends an HTTP header specified as$string.

Note: Header()must be used prior to any other output is sent to the user/browser. Use

ob_start()to workaround this.

Examples:

header('8ocation# htt#//%%%Fso&eotherlaceFco&'); //

:edirects the ser to the ro"ided :8 header('H66Q/1F-
http://www.securephpwiki.com/index.php/Email_Injectionmailto:'[email protected]'mailto:[email protected]'mailto:[email protected]'http://var/www/apps/conversion/tmp/scratch_1/http:%2F%2Fwww.someotherplace.com'http://www.securephpwiki.com/index.php/Email_Injectionmailto:'[email protected]'mailto:[email protected]'mailto:[email protected]'http://var/www/apps/conversion/tmp/scratch_1/http:%2F%2Fwww.someotherplace.com'


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Operators

When comparing or processing variables and other values you use

operators. Without them, PHP would be more of a word jumble instead of a

language. In some unique cases, operators slightly alter the relationship between two

variables or their function within PHP. Without further adieu, here they are.

Basic Operators

Add ( + ):$a = 1; $a = $a @ B; // $a is e>al to L Subtract

( - ):$s = 1-; $s = $s N B; // $s is e>al to B Multiply ( * ):$&

= ?; $& = $& 7 1-; // $& is e>al to ?-

Divide ( / ):$d = ?-; $d = $d / B; // $d is e>al to Modulus (

% ) Provides the remainder after division:$ = B; $ = $ O ?; // $ is e>al to 1

Assignment Operators

Add ( += ):$a = 1; $a @= B; // $a is e>al to L Subtract (

-= ):$s = 1-; $s N= B; // $s is e>al to B Multiply ( *= ):

$& = ?; $& 7= 1-; // $& is e>al to ?-

Divide ( /= ):$d = ?-; $d /= B; // $d is e>al to

Modulus ( %= ) Provides the remainder after division:$ = B; $ O= ?; // $ is e>al to 1

Concatenate ( .= ) Join onto the end of a string:

$c = B; $c F= ?; // $c is no% a strin*9 'B?'

See Also:

Concatenate -Join together in succession


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Comparison Operators


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Greater Than ( > ):2 > 1

Less Than ( < ):1 < 2

Greater Than or Equal To ( >= ):2 >= 2

Less Than or Equal To (


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Short-Hand Plus or Minus one

Also known as:Increment (

$integer++;) Decrement (

$integer--;)

Example:

$a = 1;

$a = $a @ 1; // $a is no% e>al to ? $a@@; // $a is no% e>al to A

$aNN; // $a is no% e>al to ? a*ain9 sa&e as $a = $a N 1;

@ - Suppress Errors

Placing the commercial at symbol (@) before a function tells PHP to suppress any

errors generated by that function.

Examples:

inclde('3oes


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PHP Reference: Beginner to Intermediate PHP5.

. .

Use this for functions when you wish to simply alter the original variable and return

it again to the same variable name with its new value assigned.

fnction add(U$"ar){ // 6he U is efore the ar*&ent $"ar $"ar@@;

}

$a = 1;

$ = 1-;

add($a);

echo 4a is $a94;

add($);

echo 4 a is $a9 and is $4; //


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Assignment ( = ): Assigns the value on the right to the variable on the left

Equality ( == ): Checks if the left and right values are equal

Identical ( === ): Checks if the left and right values are equal AND identical

Example:

$a = 1; // Sets the "ale of $a as 1 y assi*n&ent$ = 6:+; // Sets the "ale of $ to the oolean 6:+

if ($a == $){

echo 'a is e>al to F';

}

if ($a === $){

echo 'a is identical and e>al to F';

}

a is e>al to F

Not ( ! ), Not Equal to ( != ), Not Identical to ( !== )

Used in conditional statements to evaluate as true a FALSE result of an

expressionor if a value is NOT equal to the second value.

Example:

$a = 1;

if (!isset($a)){ // f the "ariale $a is al Vero

SeeThe Equal Signabove for equality versus identical

Concatenate (The Period)

A period is used to join dissimilar items as part of a string in the same order as they

are listed. In many cases this is used to reference the value of a function or of an

array, which cannot be referenced within double quotations ( "" ) when being

assigned to a$stringvariable.

Example:

$array = array( 1 = 'Hello' );$strin* = 'World';echo '$strin* in sin*le >otes9 follo%ed y ' F $array,1. F 4$strin*4;

$strin* in sin*le >otes9 follo%ed y HelloWorld

"4


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Comparison Operators (non-arithmetic)

and ( && )

or( II )

xor ( xor ) - Or, but not All

Examples:

if (1 == 1 UU ? == ?){ echo 'nd is6re';

}

nd is 6re

if (1 == 1 ? == ?){echo 't least one of these is 6re';

}

t least one of these is 6re

if (1 == 1 xor ? == 1-){echo 'ne of these is 6re9 t not oth';

}

ne of these is 6re9 t not oth

"5


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"$


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Control Structures

The heart of PHP is the control structures. Variables and arrays are lonely

without them as they facilitate comparisons, loops, and large hands telling you to go

that way and do it this way. Okay, I made that last part up. Here we go!

If, Elself, Else

if (expr) {

// f expr is 6:+9 do this9 then exit the P loo }

elseif (expr!) {// f expr is P8S+9 and expr! is 6:+9 do this9 then exit the loo }

else{

// f all expr"s are P8S+9 do this9 then exit

}

There can be only one instance ofelsein anifstatement, but multipleelseifexpressions

are allowed prior to theelsestatement.

Example:

$x = 1;

if ($x 0 1) {

echo '$x is less than 1'; }elseif ($x == 1){ // als9

for co&arison

echo '$x is e>al to 1'; }

else{

echo '$x is neither e>al to 1 or less than 1';}

$x is e>al to 1

See Also:

switch -A simpler, more organized usage than multiple if/elself

combinations

break -Stops a loop and exits regardless of if the statement evaluates as true

. . .

"7


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Alternative syntax for anifstatement:

i f (expr) #

// f expr is 6:+9 do this9 then exit the P loo elseif

( expr!):

// f expr is P8S+9 and expr! is 6:+9 do this9 then exit the

loo

else#

// f all expr"s are P8S+9 do this9 then exit endif;

Switch

s%itch (exr){ case value:

// 3o this if value &atchesrea; case

value!:// 3o this if value! &atchesrea;

defalt# // ,otional.// 3o this if no other cases &atchF 3oes not ha"e to e at the end rea;

}

expr- A$string, $integer,or$floatto be compared against

Aswitchevaluates theexpragainst any number ofcasesor options, specifying the

behavior for eachcase.Cases can be 'stacked' to allow the same portion of code to be evaluated for different

cases:

s%itch ( expr)

{ case value:

case value!:

// 3o this if value or value! &atches

}

Theswitchis evaluated line-by-line, and therefore if there was nobreakcommand,

thecasedeclaration would effectively be ignored and the code would continue to be

processed until theswitchends or abreak;is reached.

$x = 1;

s%itch ($x) {

case 1#echo '1'; //


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Examples:

$x = ?; s%itch

($x) { case 1#

echo '1';

rea;

case ?#

echo '?';

rea;

case A#

echo 'A';

rea;

}

$x = 'ho%dy';s%itch ($x)

{ case 'hi'#

echo 'Hi there';

rea;

defalt# // an e any%here9 all cases e"alated efore it is sed

echo 'Greetin*s';

rea; case

'hello'#

echo 'Hello there';

rea;

}

Greetin*s

See Also:


. . .

Alternative syntax for aswitchstatement:

s%itch ( expr):

case value:

// 3o this if value &atches

rea; case

value!:

// 3o this if value! &atches

rea;

defalt# // ,otional.

// 3o this if no other cases &atchF 3oes not ha"e to e at the end rea;

ends%itch;

while

%hile ( expr) {

// f expr is 6:+9 do this9 then e"alate expr a*ain

}

"9


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Thewhileloop checks theexprand if it evaluates as true, the script runs through the

entire contents of thewhileuntil it finishes, then it evaluates theexpragain and

repeats until theexprevaluates as false.

Example:

$x = 1;%hile ($x 0= A){

echo 4$x9 4;$x@@; // incre&ents $x y addin* 1F ShortNhand "ersion

}

19 ?9 A9

See Also:

do-while -Same aswhile,except theexpris evaluated after the first actionbreak -

Stops a loop and exits regardless of a TRUE statement evaluationcontinue -Stops

the iteration of the loop, and theexpris evaluated again

Alternative syntax for awhilestatement:

%hile (expr) #

// f expr is 6:+9 do this9 then e"alate expr a*ain

end%hile;

do-while

do {

// 3o this} %hile ( expr);

Thedo-whileloop performs whatever is inside thedostatement, checks theexpr,then

if it evaluates as TRUE, runs through the entire contents of thedountil it finishes,

evaluating theexpragain, and repeating until theexprevaluates as FALSE.

Example:

$x = 1;

do {

echo 4$x9 4;

$x@@; // Eaes $x = ?9 therefore the %hile %ill e"alate as false } %hile

($x 0= 1);

See Also:

while -Similar todo-while,except theexpris evaluated first


continue -Stops the iteration of the loop, and theexpris evaluated again

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for

for (expr#; expr!; expr$) {// f expr! is 6:+9 do this

}

When started, theforloop executesexprlonce at the beginning. Next,expr2is

evaluated. Ifexpr2is true, the code inside theforloop is executed. When theforloop

reaches the end,expr3is executed before looping and checkingexpr2again.

Example:

for ($x = 1; $x 0= B; $x@@){ echo $x;

}

1?AB

See Also:

break -Stops theforloop and exits it immediately

continue -Stops the current iteration of theforloop, andexpr3is executed before

checkingexpr2again

Alternative s%nta( ,or aforstatement:for ( expr# ; expr!; expr$):

// f expr! is 6:+9 do thisendfor;

An example ofcontinueandbreakin aforloop:

for ($"=-;$"0=1-;$"@@){ echo

$";

if ($" == B)

{ contine;

}if ($" == J)

{ rea;

}echo

}

-919?9A99BL9I9J

foreach

foreach ($array as %value) {// 3o so&ethin*

}// nother for&9 for eys and "alesforeach ($array as %&e' = %value) { // 3oso&ethin*

}

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Theforeachloop goes through all items in an array, assigning a temporary variable

name forvalueand, if chosen, thekeyas well so they can be used within the executed

code inside the loop.

Examples:

$array = array('ohn' = ?-9 'ane' = ?9 'oseh' = ?J);foreach ($array as $"ale){ echo 4$"ale9 4;}

?-9 ?9?J9foreach ($array as $na&e = $a*e){

echo 4$na&e N $a*e4;

echo '0r /'; // TH6E8}

for a line rea

ohn N ?-

ane N ?

oseh N ?J

See Also:

Pass by Reference -Using the ampersand ( & ) to alter an array throughforeach

break [$integer]

$integer- [optional] Specifies the number of nested loops to break out of

Exits and stops execution of the current (default) for,foreach, while, do-while,orswitch

loop.

Example:

$conter = -;

%hile (1 == 1){ // Will rn fore"er

%hile (- == -){ // Will also rn fore"er

$conter@@; // ncre&ent $conter ls 1 echo

$conter; if ($conter == B){ rea ?;

}

}

echo 'Pirst %hile loo'; //


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continue [$integer]

$integer- [optional] Specifies the number of nested loops to skip out ofNote:The

$integerdoes not supply the number of iterations to skip, it always only stops the current

iteration from continuing any further.

Skips the rest of the current loop iteration and if applicable, continues to the next

iteration of the loop(

3.

Example:

for ($x=1;$x0=1-;$x@@){ if

($x == B) { contine;

} // 6he echo ne"er occrs if $x == B

echo $x;

}

1?ALIJK1-

return [$variable]

$variable- [optional] The variable to be returned from a function

If used as part of a regular script and not part of a function, it works the same asexit()

ordie().Return is more commonly used as part of a function to assign a value to the

results of a function back at the original function call.

See Also:

Functions -Provides an example of returning a$variableas part of a function

exit() -Terminate the current script immediately

include(file)

file-$string

Include and evaluate thefileas part of the current script/page. This is an easy way to

store common variables, functions4, or lines of HTML that will be included by

multiple scripts/pages. Failure of the function generates an error.

Example:

inclde('so&efileFinc');

3. In te case o, aswitch, continue as te same e,,ect asbrea!

4. unctions soul& onl% be inclu&e& once# Consi&er usin inclu&eonce or re6uireonce

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include_once(file)

file-$string

Include and evaluate thefileas part of the current script/page. If the file has already

been included, it will ignore the request. This is an easy way to store common

variables, functions, or lines of HTML that will be included by multiple scripts/pages.

Failure of the function generates an error and terminates the script immediately.

Example:incldeDonce('so&efileFh');

require(file)

file-$string

Include and evaluate thefileas part of the current script/page. This is an easy way to

store common variables, functions5, or lines of HTML that will be included by

multiple scripts/pages. Failure of the function generates an error.

Example:

re>ire('so&efileFht&');

require_once(file)

file-$string

Include and evaluate thefileas part of the current script/page. If the file has already

been included, it will ignore the request. This is an easy way to store common

variables, functions, or lines of HTML that will be included by multiple scripts/pages.

Failure of the function generates an error and terminates the script immediately.

Example:

re>ireDonce('so&efileFh ' );

5 unctions soul& onl% be inclu&e& once# Consi&er usin re6uireonce

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Global Variables

While some global variables can be created through the use ofdefine(),some

are reserved because of a special function, giving access to different types of data. All

global variables listed below are arrays that may or may not contain data, dependingon the current script and environment.

$_SERVER

$_SERVER['HTTP_USER_AGENT'] - Browser description from header,H66QDS+:DG+


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$_REQUEST

Includes all variables provided by$_GET, $_POST,and$_COOKIE

$_POST

Includes all variables submitted through HTTP POST, such as an HTML form with

action="post".

$_GET

Includes all variables submitted through the query string, either manually or from a

form with action="get".

htt#//%%%F exa&le F co&/testF h>ery="ale

// tt of rintDr($DG+6) of the ao"e :8 exa&le rray

( ,>ery. = "ale )

$_SESSION

Variables assigned to the current session.

$_COOKIE

Any cookies stored for the current website. Only visible after the page was reloaded

if it was just set usingsetcookie().

See Also:

setcookie() -Assigning and deleting cookies

$_FILES

Variables provided to the script via POST uploads.

$_ENV

A collection of variables about the server environment.

$GLOBALS

Contains a reference for all variables, global or otherwise, in the script.

3$
http://www/http://www/


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Variable Functions

The following functions check details about variables themselves, rather

than addressing a specific aspect of atypeof variable. Put another way, you don't

want to know what type of elephant you have, just that it is an elephant, and it is

about to trample you. Too much? Oh well, here we go again.

empty($variable)

Determine whether the$variableis empty. Returns TRUE if the$variableis:

'' - Empty$string

0 - For an$integer

'0' - For a$string

array() - For an$array

NULL

FALSE

An undeclared variable

Example:

$strin* = 'Hello';

$array = array();"arDd&( e&ty($strin*)9 e&ty($array)9 e&ty($3oes


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Example:

$strin* = 1 1 ;

$inte*er = -;

$array =


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Example:

$array = array();$array? = array( 'one'9 't%o'9 'three' );

"arDd&( isDarray($array)9 isDarray($array?) );

ool(tre) ool(tre)

is_int($variable)

Also known as:is_integer()

Determine whether the$variableis an integer. Returns TRUE if it is an integer.

Example:

$int = -;

$strin* = '-';

"arDd&( isDint($int)9 isDint($strin*) );

ool(tre) ool(false)

is_string($variable)

Determine whether the$variableis a string. Returns TRUE if it is a string.

Example:

$int = -;

$strin* = '-' ;

"arDd&( isDstrin*($int)9 isDstrin*($strin*) );

ool(false) ool(tre)

is_numeric($variable)

Determine whether the$variableis an integer or a numeric string(e.g."12"). If either

is true, it will return TRUE.

Example:

$int = 1-; $strin*

= '1-';

"arDd&( isDn&eric($int)9 isDn&eric($strin*) );

ool(tre) ool(tre)

See Also:

is_int() -Determine if a variable is an integeris_string() -Determine if a variable is an string

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Mario Lurig

var_dump(expr [,...expr...])

Accepts multiple expressions, separated by commas

expr- A$variableor any expression that generates a result

Shows the type of variable and its value in the following format:

t'pe(value) // When e"alatin* a oolean9 inte*er9 or float strin*(length)

value // When e"alatin* a strin* array(len*th) { value } // When

e"alatin* an array

Example:

$inte*er = 1-; $strin* =

'Hello'; $array =

array( 'one' );

"arDd&( $inte*er9 $strin*9 $array9 isDstrin*($strin*) );

int(1-) strin*(B) 4Hello4 array(1) { ,-.= strin*(A) 4one4 }

ool(tre)

See Also:

echo -Prints the value of a$scalar

. . .

Surroun&in te var_dump()'it te / tas 2)re 2)re 'ill )resent te out)ut o,

multi)le e()ressions in a more uman rea&able ,ormat#

// sin* the sa&e "ariales as ao"e echo

'0re';

"arDd&( $inte*er9 $strin*9 $array9 isDstrin*($strin*) );

echo '0/re';

print_r($variable)

Output the contents of$variable6.Typically used to display the contents of an array.

Example:

$array = array( 'le'9 'ran*e'9 'Eelon' );rintDr($array);

rray ( ,-. = le ,1. = ran*e ,?. = Eelon )

See Also:

echo -Display the value of a$scalar

$ I, Svariable isboolean+ ;


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PHP Reference: Beginner to Intermediate PHP5.

. .

If you add the HTML tags around the output, formatting will be easier

to follow.

$array = array( 'le'9 'ran*e'9 'Eelon' );

echo '0re'; rintDr($array); echo '0/re';

rray

(,-. = le,1. = ran*e,?. = Eelon

)

Here is a quick function to do this easily:,fnction rerint($array){

echo '0re'; rintDr ($array); echo '0/re'; lserialize(value)

Converts thevalueto a storable representation in a$string.

Example:

$array = array( 'one'9 't%o'9 'three' );

$ott = serialiVe($array); echo$ott;

a#A#{i#-;s#A#4one4;i#1;s#A#4t%o4;i#?;s#B#4three4;}

See Also:

unserialize() -Convert a serialized string back into its originalvalue

If adding the serialized data to a MySQL database, you will need to escape some

characters usingaddslashes()and then remove them again withstripslashes()when

recovering the value from the database.

$array = array( 'one'9 't%o'9 'three' );$dDready = addslashes(serialiVe($array));

// add $dDready to yor dataase (code not inclded here) //

retrie"e it fro& the dataase (code not inclded here) $nor&al =

nserialiVe(strislashes($dDready));

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Mario Lurig

unserialize($string)

Converts a serialized$stringback into its original value.Example:

$array = array( 'one'9 't%o'9 'three' );$ott = serialiVe($array);

echo '0re ' ;

"arDd&($ott);

rintDr( nserialiVe($ott) );

echo '0/re ' ;

strin*(B-) 4a#A#{i#-;s#A#4one4;i#1;s#A#4t%o4;i#?;s#B#4three4;}4

rray

(,-. = one,1. = t%o,?. = three

)

See Also:

serialize() -Convert avalueto a storable representation in a$string

floatval($scalar)

Returns the float value of the$scalar.

Note:If the$scalaris a string starting with integers, characters after the integers will be

stripped out.

Example:

$float = 1FA;

$strin* = 41Bthe %ords4;

$strin*? = 4--?B4;

"arDd& ( float"al($float)9 float"al($strin*)9 float"al($strin*?) );

float(1FA) float(1B) float(?B)

. . .

As in the example above, if a string starts with integers and has trailing characters,

you can convert this to a float with this command. However, if you intend to use this

function to retrieve the string equivalent, any leading zeros will be erased. Be careful!

4"


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String Functions

If you were a cat, string functions would be the cat's meow, all puns

intended. Besides being a large part of your PHP code, they provide much of the

functionality to identify and alter your data into other formats, such as arrays.

addslashes($string)

Adds backslashes (escape string) to items within$stringto make it safe for database

queries. Effects single quotes ( ' ), double quotes ( " ), backslashes ( \ ), and the NUL

byte.

Example:

$strin* = ' 6o& said9 4Earcs is &ad!4'; echo

$strin*;

$strin* = addslashes($strin*); echo

$strin*;

6o& said9 4Earcs is &ad!4 6o& said9 54Earcs is &ad!54

See Also:get_magic_quotes_gpc -Server setting for automatically applying addslashes to

GET/POST/COOKIE data

stripslashes() -Remove the backslashes created byaddslashes()

stripslashes($string)

Removes backslashes (escape string) from items within$stringadded

throughaddslashes()ormagic_quotes_gpc.

Example:

$strin* = ' 6o& said9 4Earcs is &ad!4';

$strin* = addslashes ($strin*); echo $strin*;$strin* = strislashes($strin*);

echo $strin*;

6o& said9 54Earcs is &ad!54 6o& said9 4Earcs is &ad!4

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See Also:

get_magic_quotes_gpc -Server setting for automatically applying

addslashes to GET/POST/COOKIE data

addslashes() -Adds backslashes to make a string safe for database queries

chunk_split($string [,length][,endstring])

length- [optional]$integerdefault:76

endstring- [optional]$stringdefault:"\r\n" (carriage return and new line)

Splits$string

into sections oflengthcharacters, every section is terminated with theendstring.Evaluates only the character length to generate the resulting string.

Example:

$strin* = 'Hello


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$strin* = 'Hello


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count_chars($string [,mode])

mode- [optional]$integer(0, 1, 2, 3, or 4)default:0

Values: 0 - Returns an array with the count for all characters

5. - Returns an array with the count for all characters with at least one

instance in$string

6. - Returns an array with the count for all characters with zero

instances

7. - Returns a string of all characters contained within$string

8. - Returns a string of all characters not contained within$string

Checks$stringfor instances of all ASCII characters and counts the number of times

that a character is included within the string. Output varies depending onmode.Note:The key in the array is the ASCII byte-value of the character (modes 0-2) while the

string output is the characters themselves (modes 3 and 4).

Examples:

$strin* = 'Hello';

$array = contDchars($strin*9 1);

echo '0re'; // ired9 inclded for easier readaility

rintDr($array);

rray

(

,I?. = 1

,1-1. = 1

,1-J. = ?

,111. = 1

strin*() 4Helo4

See Also:

chr() -Get the ASCII character represented by its byte-value

4$

$sedcharacters = contDchars($strin*9 A);

"arDd&($sedcharacters);

)

foreach ($array as $ey = $"ale){

$char = chr($ey); // haracter reresented y the yteN"ale

$chararray,$char. = $"ale; // Eae ne% array %ith characters

}rintDr($chararray);

rray(

,H. = 1,e. = 1,l. = ?

,o.) = 1


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chr($integer)

$integer- 0 - 255

Returns the single character string representation of the ASCII byte-value

($integer)

Example:

echo chr(I?); H

echoargument[,...argument...]

Accepts multiple arguments separated by a comma argument- A$scalaror function

with scalar outputOutputs the value of theargumentto the user.

Example:

echo 'Hello

' ; Hello

printargument

argument- A$scalaror function with scalar outputOutputs the value of the

argumentto the user, always returns 1. Useecho()instead.

Example:

$x = rint 'Hello';

rint $x;

Hello

explode(delimiter,$string [,limit])

delimiter-$string,if set to '', explode will return FALSElimit-

[optional]$integer,default:no limit

Returns an array of strings created by searching through$stringand separating it

by using the provideddelimiteras the separation point.Limitsets the maximum

number of elements, with the last element of the array being the remainder of the

string}7

7

8

.

47

1. Sboolean is re)resente& b% 1 ;


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rray

(,-. = -?

,1. = -1N1KJ-

See Also:

implode() -Creates a string from array elements, using a joining string

. . .

As shown above, explode can be used to break apart common language syntax, such

as separating a paragraph submitted by a user into its individual sentences, or

allowing a user to submit tags for a particular item, separated by commas, and then

explode()those items for database storage.

48

Example:

$array = exlode.'N'9 $exlode&e9 ?); // 8i&it to ? ele&entsrintDr($array);

$exlode&e = '-?N-1N1KJ-';

$array = exlode.'N'9 $exlode&e); // dash (N) is the deli&iter

echo '0re'; // Por easier readaility rintDr($array);

rray(

,-. = -?,1. = -1,?. = 1KJ-

im lode(limiter, $arra)limiter-$string

Returns a string containing the contents of$arrayjoined by the providedlimiter.

Example:

$array = array. 'Hello'9 'World'9 '!' );

$strin* = i&lode.' '9 $array); // sin* a sace as the limiter echo

$strin*;

Hello World !

See Also:

explode() -Separate a string into an array using a specific delimiting string


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sprintfformatting, inputs [, ...inputs...]

Accepts multiple inputs to be used when specified in formatting

formatting-$stringspecific formatting string, explained belowinputs-$scalar(s) to

be formatted

Returns a formatted stringformatting,using theinputsto dynamically input their

values into the formatted string using a preset set of rules, specified below.

The following is the available nomenclature for theformattinginput.

49

Every time an input is expected to be used and evaluated as part of the formatted

string, it is preceded by a percent sign ( % ), followed by the specifiers/rules:

Note:All specifiers, excluding thetypespecifier, are optional.

Asignspecifier. Placing a plus sign ( + ) forces negative AND positive signsto be visible (only negative values are specified by

default).

Apaddingspecifier. The default is a space, and does not need to bespecified. A zero ( 0 ) can be used as well without any secondary notation. If

any other character is to be used, it should be preceded with a single quote

( ' ).

Analignmentspecifier. The default is right-justified (thus padding is placedon the left of the string). Placing a dash/subtract ( - ) will set it to left-

justified.

Awidthspecifier. This integer determines the minimum length incharacters the output should be. When combined with padding, the

specified width minus the input's length determines the number of padded

characters that will be added.

Aprecisionspecifier. A period ( . ) followed by an integer, sets the numberof decimal places that should be output for a float. If used on a string, it sets

a maximum character limit for the output.

Atypespecifier:

%- a literal percent sign, thus would be written %% to display a percent

sign in the formatting string

b- the input should be an integer, a binary number is the output.


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PHP Reference: Beginner to Intermediate PHP5Usingpaddingand

widthusing a custom character, the asterisk ( * )

$endofass%ord = '%ord';

$ott = srintf(4or ass%ord# O'7Js49 $endofass%ord); echo

$ott;

or ass%ord# 7777%ord

Usingpadding, alignment(left), andwidth

$endofass%ord = '%ord';

$ott = srintf(4or ass%ord# O'7NJs49 $endofass%ord); echo $ott;

or ass%ord# %ord7777

Using theprecisionspecifier

$scientific = 1F?eA;

echo srintf(46hree deci&al laces# OFAe49 $scientific); 6hree

deci&al laces# 1F?--e@A $float = 1F?eA;

echo srintf(46%o deci&al laces# OF?f49 $float); 6%o

deci&al laces# 1?--F-- $strin* = 'Hello World!';

echo srintf(4tNoff after characters# OFs49 $strin*); tNoff

after characters# Hell

See Also:

printf() -prints a formatted string results rather than simply returning themsscanf() -

Parses a string through a formatted string, reverse ofsprintf()

? @ ? ? @ ? ? @ ?

For MySQL security, you can usesprintf()to force user input to have a

maximum length and be valid for the structure of your database. Use the

precisionspecifier to automatically parse the string submitted by GET or

pOST._____________________________________________________________________

printf(formatting, inputs[, ...inputs... ]

Accepts multiple inputs to be used when specified in formatting

formatting-$stringspecific formatting string.Seesprintf()for nomenclature inputs-

$scalar(s) to be formatted

Prints a formatted stringformatting,using theinputsto dynamically input their values

into the formatted string using a preset set of rules.Note:Seesprintf()for rules for

formatting strings.

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Mario Lurig

Example:

$strin* = 'ies';

rintf(4 thin Os are cteF49 $strin*);

thin ies are cteF

See Also:

sprintf() -Returns the formatted string, explains rules/nomenclature

sscanf($string,formatting[, ...outputs... ]

Accepts multiple [optional] outputs, but changes the behavior of the function

Examines the given$stringand parses it based on the expectedformatting.Returns an

array when nooutputsare included. Ifoutputsare included, they specify by reference

the variable names to assign the formatted contents.Note:Seesprintf)for rules for

formatting strings -typespecifiers.

Examples:

See Also:

sprintf() -Reverse ofsscanf()and provides explanation of formatting stringslist() -

Assigns the values of an array to variable names

|htmlspecialchars($string [,quotes_flag][,character_set])

quotes_flag- [optional]$stringdefault:ENT_COMPAT (double quotes only) Other

values: ENT_QUOTES (both single and double quotes)

ENT_NOQUOTES (neither double nor single)

character_set- [optional]$stringdefault:ISO-8859-1

Converts some characters in$stringwith special meaning in HTML to their safe

HTML entities. This includes (but may be limited by some optional

5"

$strin* = '1?/1/1KJ-' ;

$ottsDcont = sscanf($strin*9 4Od/Od/Od49 $&onth9 $day9 $year);

"arDd& ($&onth9 $day9 $year);

int(1?) int(1) int(1KJ-)

$strin* = '1?/1/1KJ-' ; $array =

sscanf($strin*9 4Od/Od/Od4); echo

'0re'; // Por i&ro"ed readaility

rintDr($array);

rray

(,-. = 1?,1. = 1

,?.) = 1KJ-


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flags): double quotes ( " ), single quotes ( ' ), greater than ( > ), less than ( < ), and

ampersand ( & ).

Example:

$strin* = '0stron*Hello U World!0/stron*0r /'; echo

ht&lsecialchars($strin*);

HTML source code:

Ult;stron*U*t;Hello Ua&; World!Ult;/stron*U*t;Ult;r /U*t;

See Also:htmlspecialchars_decode()- Reverses the effect ofhtmlspecialchars()

htmlentities()- Effects all HTML entities, not just the five above

|htmlspecialchars_decode($string [,quotes_flag])




Converts HTML entities back to the character representation in$string.This includes

(but may be limited by some optional flags): double quotes ( " ), single quotes ( ' ),

greater than ( > ), less than ( < ), and ampersand ( & ).

Example:

$strin* = 'Ult;stron*U*t;Hello Ua&; World!';echo ht&lsecialcharsDdecode($strin*);

HTML source code:

0stron*Hello U World!

See Also:

htmlspecialchars()- Converts the five items above into their HTML entities

html_entity_decode()- Effects all HTML entities, not just the five above

|htmlentities($string [,quotes_flag][,character_set])




character_set- [optional]$stringdefault:ISO-8859-1

Converts some characters in$stringwith special meaning in HTML to their safe

HTML entities. This includes (but may be limited by some optional flags): double

quotes ( " ), single quotes ( ' ), greater than ( > ), less than ( < ), and ampersand ( & ).

53


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Example:

$strin* = 40stron*'Hello World!'4; echo

ht&lentities($strin*9 +otes not con"erted

HTML source code:

0stron*U[-AK;Hello World!U[-AK;

See Also:

htmlentities()- Converts all HTML entities

htmlspecialchars_decode()- Decodes five specific HTML entities

trim($string [,characters])

characters- [optional]$string

Remove from the beginning and end of$stringthe following characters whencharactersis not included: whitespace (' '), tab (\t), new line (\n), carriage return (\r),

NUL byte (\0), and the vertical tab (\x0B). Ifcharactersis included, that list is used

instead9.

Note:Once a character not from the list is reached, trimming halts.

Examples:

$strin* = 4 5n Hello World! 5t5t4;

echo tri&($strin*);

54

9 *itin characters, a &ouble )erio& ## can s)eci,% a rane (e.g. a## is a trou


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echo tri&($strin*9 4 5t5n!r4);

// r %ill not e re&o"ed ecase d is not in the list Hello

World

echo tri&($strin*9 4 5t5n!dFFr4); // ran*e of d thro*h r (lo%ercase) Hello W

See Also:

ltrim() -Trim only from the beginning of the stringrtrim() -

Trim only from the end of the string

ltrim($string [,characters])

characters- [optional]$string

Remove from the beginning of$stringthe following characters whencharactersis not

included: whitespace (" "), tab (\t), new line (\n), carriage return (\r), NUL byte (\0),

and the vertical tab (\x0B). Ifcharactersis included, that list is used instead10.

Note:Once a character not from the list is reached, trimming halts. Examples:

$strin* = 4 5n Hello World!4;

echo ltri&($strin*);

echo tri&($strin*9 4 5nFFHaFFV4);

// ll caital letters et%een and H9 and all lo%ercase letters World!

See Also:

trim() -Trim from the beginning and the end of the stringrtrim() -Trim only from the end of the string

rtrim($string [,characters])

Also known aschop()characters-

[optional]$string

Remove from the end of$stringthe following characters whencharactersis not

included: whitespace (" "), tab (\t), new line (\n), carriage return (\r), NUL byte (\0),

and the vertical tab (\x0B). Ifcharactersis included, that list is used instead10.

Note:Once a character not from the list is reached, trimming halts.

10 *itin characters, a &ouble )erio& can s)eci,% a rane (e.g. a## is a trou

55


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Examples:

$strin* = 4Hello World?! 5t5t4; echo

tri&($strin*);

Hello World?!

echo tri&($strin*9 4 5t!-FFK4);

// :an*e inclded is all n&ers et%een - and K Hello

World

See Also:ltrim() -Trim only from the beginning of the stringtrim() -Trim

from the beginning and the end of the string

crypt($string [,salt])

salt- [optional]$string

Performs a one-way hashing encryption on$stringusing an algorithm specified by

the system11. Thesaltcan be used to generate a stronger encryption, but when not

specified and generated by the system, it will be created once per run of the script.

Example:$ass%ord = '&yass%ord';echo cryt($ass%ord); // tt %ill "ary

See Also:

md5() -MD5 algorithm based encryption, portable, more secure, commonly used

sha1() -Shal algorithm based encryption, portable, most secure

md5($string [,raw_flag])

raw_flag- [optional]$booleandefault:FALSE, 32-character hexadecimal

Performs a one-way hashing encryption on$stringusing the MD5 Message-Digest

Algorithm. If theraw_flagis set to TRUE, it returns a raw binary format with a

length of 16 characters.

Example:

$ass%ord = '&yass%ord';

echo &dB($ass%ord);

A J1KdIeeaK? L-aBcJBcJBAe

5$

11 So,t'are movin bet'een )lat,orms ma% ave &i,,erent encr%)tions+ an& tus 'ill cause

)roblems 'it com)atibilit%# Best to use m&5 or sa1 instea& ,or )ortabilit%


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See Also:

sha1() -Sha1 algorithm based encryption

. . .

For better security in storing user passwords, the use of a salt should be considered.

The salt is basically a string added onto the supplied$stringto increase its length

and complexity. In the case of user passwords, it would be randomly created by the

system then saved to the database as a separate entry in the database from the

password for that user. This helps protect against reverse md5 dictionary attacks.

$ass%ord = 'ass%ord'; // Xery ad ass%ord

$salt = sstr(&dB(ni>id(&tDrand()9 6:+))9 -9 B); // B char9 salt

$saltedDass%ordDhash = &dB($salt F &dB($ass%ord)); echo

$saltedDass%ordDhash; // tt "aries

d1?A KdccLe-1I BI ?eaLfedBdf-dLe-Ie

57

md5_lelename [, raw_a])filename-$string


Generates the MD5 hash of a file withfilename.If theraw_flagis set to TRUE, it

returns a raw binary format with a length of 16 characters.

Example:

$hash = &dBDfile('so&efileFtxt');

See Also:

md5() -MD5 algorithm based encryption for a string

sha1($string [,raw_flag])raw_flag- [optional]$booleandefault:FALSE, 40-character hexadecimal

Performs a one-way hashing encryption on$stringusing the US Secure Hash

Algorithm. If the raw_flag is set to TRUE, it returns a raw binary format with

a length of 20.

Example:

$ass%ord = '&yass%ord';

echo sha1($ass%ord);

K1dfdKdd1KJaffcBc1KcdJceLdAA Jfde I -e?


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See Also:

md5() -MD5 algorithm based encryption, commonly used

? @ ? ? @ ? ? @ ?

please seemd5()tip for adding a salt to a password for extra security"

58

sha1_file(lename[,raw_ag])filename-$string


Generates the Sha1 hash of a file withfilename.If the raw_flag is set to TRUE, it

returns a raw binary format with a length of 20.

Example:

$hash = sha1Dfile('so&efileFtxt');

See Also:

sha1() -Sha1 algorithm based encryption for a string

number_format( $float [,decimals][,decimal_point, thousand_separator]decimals- [optional]$integerdefault:0, no decimal places

decimal_point- [optional]$stringdefault:period ( . )

thousand_separator- [optional]$stringdefault:comma ( , )

Format the$floatwith thousand separating and decimal places, if specified.Note:

Rounding occurs if the float has more values than the formatting specifies.

Examples:

$float = 1?ABLIFJK1;

echo n&erDfor&at($float);

19?A9BLJ

echo n&erDfor&at($float9 ?); // S notation

19?A9BLIFJK

echo n&erDfor&at($float9 ?9 4 4); // Prench for&attin*

1 ?A BLI9JK

nl2br($string)Replaces all instances of the new line ( \n ) formatting character in$stringwith

the XHTML line break
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Example:

$strin* = 4Hello5nWorld4;

echo nl?r($strin*);

HTML Source Code:

Hello0r /World

Standard output:

Horld

parse_str($string [, $array])

Examines$stringas a query string and assigns the variables with names equal to the

query's key, then assigning values equal to the query's value. If$arraywas specified,

query variables will be assigned to an array instead with the same key => value

association.

Note:Output is affected by the magic_quotes_gpc setting the same as $_GET. Examples:

$>eryDstrin* = 'ey="aleUcolor=red';

arseDstr($>eryDstrin*);

echo 45$ey e>als $ey9 and 5$color e>als $color4;

$ey e>als "ale9 and $color e>als red

$>eryDstrin* = 4ey="aleUcolor='red'4;

arseDstr($>eryDstrin*9 $array);

echo '0re'; // Por easier readaility

rintDr($array);

Without magic_quotes_gpc enabled:rray

(

,ey. = "ale

,color. = 'red'

With magic_quotes_gpc enabled:

rray

(

,ey. = "ale

,color. = 5'red5'

See Also:

get_magic_quotes_gpc -Check if magic quotes is enabledlist() -

Assign contents of an array to variables

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This is a handy way to easily convert all the query submitted keys/values from

$_SERVER['QUERY_STRING'] into variables using the following:

arse str($ S+:X+:,1 2+: S6:


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$findarray = array('l'9 'o');

$relace = 'x'; $strin* =

4Hello4;

$ne%strin* = strDrelace($findarray9 $relace9 $strin*); echo

$ne%strin*;

See Also:

str_ireplace() -Case-insensitive version ofstr_replace()

strtr()- Simplified variation that also does not repeat onfind/replace

str_ireplacefind,replace, subject [, count])

find-$stringor$array

replace-$stringor$array

subject-$stringor$array

count- [optional]variable name - $integer

Replaces all instances offindwithreplacewithinsubject.If subject is an array, thefindandreplaceoccurs on all entries within the array. If find and replace are arrays, the

entire string is processed for each entry in the arrays, finding the first entry infindand

replacing it with the first entry inreplace,then repeating with the next set of entries. If

there are more values in thefindarray than thereplacearray, an empty string ('') is

used as the replacement. Iffindis an array andreplaceis a string,replaceis used for

every entry infind.

The optionalcountvariable will be set with the total number of replacements that

occurred.

Note:This function is case-insensitive.

Example:

$ne%strin* = strDirelace('find'9 'relace'9 ' %ill P


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strtr($string,find, replace)

strtr($string,replace_array)

find-$stringreplace

-$string

replace_array-$array,associativefind=>replace

This function behaves differently if presented with either three arguments (single

find/replace) or two arguments (uses an array of find/replace). With three

arguments, all instances offindinside of$stringare replaced withreplace.With two

arguments, each entry ofreplace_arrayis processed so that the key is replaced with the

value.

Note:Unlikestr_replace(),only the original values of$stringwill be subject to the

find/replace.

Example:

echo strtr(' lie do*s'9 'do*'9 'cat');

lie cats

$array = array( 'find' = 'relace'9 'relace' = 'find');

$strin* = ' %ill find and then relace'; $ne%strin* =

strtr($strin*9 $array); echo $ne%strin*;

%ill relace and then find

See Also:

str_replace() -A more flexible method of replacing items within a string

substr($string,start [, length])

start-$integer,if negative, starts counting from the end of$stringlength- [optional]

$integerdefault:strlen($string)if negative, number of characters left off from the end

of$string

Returns only a portion of string starting with the character after numberstartand

optionally forlengthcharacters long.

Examples:

echo sstr('1?ABLIJK-'9 A);

BLIJK\

echo sstr('1?ABLIJK-'9 NA9 1); echo

sstr('1?ABLIJK-'9 NA9 N1);

$"


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substr_replace(subject, replace, start [, length])

subject-$stringor$array

replace-$string

start-$integer,if negative, counts from the end of the stringlength-

[optional]$integerdefault:strlen($string)

Replaces text till the end of the string withinsubjectwithreplacestarting after

character numberstart.Iflengthis specified, onlylengthnumber of characters after

startare replaced withreplacewhenlengthis positive. Iflengthis negative, it represents

the number of characters to stop replacing from the end of the string.

Ifsubjectis an array, the function returns an array instead of a string, with the

replacement processed on every entry in the array.

Examples:

$strin* = sstrDrelace('1?A B LI J K-'9 'hello'9 A);

echo $strin*;

1?Ahello

echo sstrDrelace('1?ABLIJK-'9 'hello'9 A9 ?);

$array = array('1?ABLIJK-'9 '-KJILBA?1'); $array =

sstrDrelace($array9 'hello'9 NA9 N?);

rintDr($array);

rray ( ,-. = 1?ABLIhelloK- ,1. = - KJI LBhello?1 )

See Also:

str_replace() -A find and replace of specific strings or array contents

substr_count(haystack, needle[,start][,length])

haystack-$string

needle-$string

start- [optional]$integer,must be 0 or a positive numberlength-

[optional]$integer,must be 0 or a positive number

Returns the total number of instances ofneedleinhaystack.Ifstartis provided, it

ignoresstartnumber of characters from the beginning. Iflengthis provided, it only

checkslengthcharacters fromstart.

Examples:

echo sstrDcont('acdef9 'c');

$3


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1

echo

sstrDcont('acdef9 'c'9 A);

$4


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str_pad($string,pad_length[,pad_string] [, type])

pad_length-$integer,must be positive and greater than strlen($string)pad_string-

[optional]$stringdefault:space (' ')type- [optional]$integer(0, 1, or 2)default:0

(pad right side only) Other values: 1 (pad left side only) 2 (pad both sides)Inserts

into$stringspaces or the optionalpad_stringtill$stringispad_lengthnumber of

characters long.

Examples:

$strin* = 'Hello';echo '0re'; // So refor&atted text is sho%n echo

strDad($strin*9 I)9 '!';

$strin* = 'Hello';

echo strDad($strin*9 1-9 '['9 ?);

[[Hello[[[

See Also:

sprintf()- More complex function designed for formatting strings

str_repeat($string,multiplier)multiplier-$integer

Returns a string with$stringrepeatedmultipliertimes.

Example:

echo strDreeat('1?A'9 A);

str_shuffle($string)

Randomly shuffles the characters in a string. A string jumble, essentially.Example:

echo strDshffle('Hello World!');

HreW! ollodl

1" a&&in caracters are alternate& one-b%-one+ rit si&e ten le,t si&e

$5


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str_split($string[, length])

length- [optional]$integer

Returns an array of$stringseparated by each character or the optionallengthnumber

of characters.

Examples:

$array = strDslit('Hello');

rintDr($array);

rray ( ,-. = H ,1. = e ,?. = l ,A. = l ,. = o )

$array = strDslit('Hello'9 ?);rintDr($array);

rray ( ,-. = He ,1. = ll ,?. = o )

See Also:

chunk_split() -Splits a string after a specific length with \r\n and returns a string

str_word_count($string [,option][,characters])

option- [optional]$integer(0, 1, or 2)default:0 (returns: number of words) Other

values: 1 (returns: array containing all words found) 2 (returns: array withposition

=>word) characters- [optional]$string

Counts the number of words inside$stringand returns that count by default (can be

altered byoptions).Ifcharactersis present, it contains any characters that should be

considered the same as a letter.

Examples:

$strin* = 'Welco&e to the Rn*le'; echo

strD%ordDcont($strin*);

$strin* = 'Welco&e to the RnA*le'; $%ithot =

strD%ordDcont($strin*9 -); $%ithchar =

strD%ordDcont($strin*9 -9 'A'); echo 4Withot#

$%ithot9 Withhar# $%ithchar4;

Withot# B9 Withhar#

$$

$strin* = 'Welco&e to the Rn*le'; echo

'0re'; // Por easier readaility $array =

strD%ordDcont($strin*9 1); rintDr($array);

rray

(,-. = Welco&e,1. = to,?. = the


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,A. = Rn*le

$array = strD%ordDcont($strin*9 ?);

rintDr($array);

rray

(

,-. = Welco&e

,J. = to ,11.

= the ,1B. =

Rn*le

)

strip_tags($string [,allowed_tags])

allowed_tags- [optional]$string

Remove HTML tags and comments from$string.If specific tags should be excluded,

they can be specified insideallowed_tags.

Examples:

$strin* = 406his is a ara*rahF 0/0stron*ay!0/stron*4; echo

striDta*s($strin*)9 striDta*s($strin*9 '0');

HTML Source Code:

6his is a ara*rahF ay!

echo striDta*s($strin*9 '0');

06his is a ara*rahF 0/ay!

See Also:

htmlspecialchars() -Convert HTML special characters to their entity equivalent

strpos(haystack, needle[,start])

haystack-$string

needle-$string

start- [optional]$integer

Returns the position (number of characters from the beginning ofhaystack)of the firstoccurrence ofneedleinhaystack.Ifstartis included, searching begins afterstart

number of characters.

Note:If needle is not found in haystack, FALSE is returned. See tip below. Example:

$strin* = 'nd no% for so&ethin* co&letely different';

$needle = 'thin*';

echo stros($strin*9 $needle);

1L

$7


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See Also:

strrpos() -Finds the last occurrence ofneedleinhaystack

stripos() -Finds the first occurrence ofneedleinhaystack,case insensitive

. . .

Note the following difference in evaluating the output of this function:

$strin* = 'hello';

$needle = 'h';

if (stros($strin*9$needle) == P8S+){ // e"alatin* e>ality echo '


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strpos() -Finds the first occurrence ofneedleinhaystack

strripos() -Finds the last occurrence ofneedleinhaystack,case insensitive

stripos(haystack, needle [, start])

haystack-$string

needle-$string

start- [optional]$integer

Returns the position (number of characters from the beginning ofhaystack)of the firstoccurrence ofneedleinhaystack,case insensitive. Ifstartis included, searching begins

afterstartnumber of characters.

Note:If needle is not found in haystack, FALSE is returned. Seestrpos()for tip. Example:

$strin* = 'nd no% for so&ethin* co&letely different';

$needle = '


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strrpos() -Finds the last occurrence ofneedleinhaystack,case sensitivestripos() -

Finds the first occurrence ofneedleinhaystack,case insensitive

strstr(haystack, needle)

haystack-$string

needle-$string

Find ifneedleis found inhaystackand returns the first occurrence ofneedleto the end

ofhaystack.

Note:If needle is not found in haystack, FALSE is returned. Example:

$strin* = '%%%Fexa&leFco&';

$needle = 'exa&le';

echo strstr($strin*9 $needle);

exa&leFco&

See Also:

stristr() -case insensitive version ofstrstr()

stristr(haystack, needle)

haystack-$string

needle-$string

Finds ifneedleis found inhaystackand returns the first occurrence ofneedleto

the end ofhaystack,case insensitive.

Note:If needle is not found in haystack, FALSE is returned.

Example:

$strin* = '%%%Fexa&leFco&';

$needle = '+TEQ8+';

echo stristr($strin*9 $needle) ;

exa&leFco&

See Also:

strstr() -case sensitive version ofstristr()

strlen($string)

The length of$string,or 0 if it is empty.
http://var/www/apps/conversion/tmp/scratch_1/http:%2F%2F'www.example.com'http://var/www/apps/conversion/tmp/scratch_1/http:%2F%2F'www.example.com'http://var/www/apps/conversion/tmp/scratch_1/http:%2F%2F'www.example.com'http://var/www/apps/conversion/tmp/scratch_1/http:%2F%2F'www.example.com'


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$strin* = 'Hello!'; echo

strlen($strin*);

strtolower($string)

Converts all characters in$stringto lowercase and returns the new string.

Example:

$strin* = 'Eario 8ri*';echo strtolo%er($strin*);

&ario lri*

strtoupper($string)

Converts all characters in$stringto uppercase and returns the new string.Example:

$strin* = 'Eario 8ri*';echo strtoer($strin*);

E: 8:G

ucfirst($string)Converts the first character in$stringto uppercase and returns the new string.

Example:

$strin* = 'i %ish i had so&e caitaliVation'; echocfirst($strin*);

%ish i had so&e caitaliVation

ucwords($string)

Converts the first alphabetic characters of words in$stringto uppercase and returns

the new string.

Example:$strin* = 'i %ish i had Athree so&e caitaliVation'; echo

c%ords($strin*);

Wish Had Athree So&e aitaliVation

71

Example:


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strpbrk(haystack,characters)

haystack-$string

characters-$string

Find if any of the characters inneedleare found inhaystackand returns the first

occurrence of the character found inneedleto the end ofhaystack.Note:If needle is not

found in haystack, FALSE is returned.

Example:

$strin* = '%%%Fexa&leFco&/indexFht&';

$needle = 'F/c';echo strr($strin*9 $needle); // Pinds the eriod (F) firstFexa&leFco&/indexFht&

See Also:

strstr()- Same asstrpbrk()but searches for a string instead of characters

strrev($string)

Reverses a string.

Example:

echo strre"('hello %orld');

dlro% olleh

72
http://var/www/apps/conversion/tmp/scratch_1/http:%2F%2F'www.example.com%2Findex.htm'http://var/www/apps/conversion/tmp/scratch_1/http:%2F%2F'www.example.com%2Findex.htm'


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Array Functions

It took me a while to learn about arrays, they were these scary things with

keys and values, associative and indexed, and then you could have an array inside an

array... I was scared. Truth was, they were infinitely useful in keeping things

organized, efficient, and quick. Withoutforeach,code would be bloated 2-3 times

what it could be. So don't be scared, and learn to love arrays.

One quick note:For easier readability, the output in this section is surrounded by the

HTML (preformatted) tag for easier readability if an array contains more thanone entry. Unlike all other chapters where it is included in the supplied code, it is not

in this chapter as a space consideration.

Array Nomenclature

Common usage and syntax for arrays.

Example:

$array = array(); // 3efine $array asFFF an array

$array = array( '"ale'9 't%o'9 'three' ); // ndexed array

$array = array( 'ey' = '"ale'9 'Ro' = 'slacer' ); // ssociati"e

$array = array();

$array,. = '"ale'; // ssi*n value to next a"ailale indexed ey $array,-. =

'"ale'; // ssi*n value to the ey of - $array,'na&e'. = '"ale'; // ssi*n

value to the ey name

// ssi*n the "ale of ey - in $array to $"ale $"ale =

$array,-.;

// ssi*n the "ale of the ey name in $array to $"ale $"ale= $array,'na&e'.;

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array_change_key_case($array [,option])

option- [optional]$integer(0 or 1)default:0 (lowercase) Other

value: 1 (uppercase)

Changes the case of the keys inside of$arrayto lowercase(default)or

uppercase.

Examples:

$array = array( '


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(,Ro. = dad

)

array_combine(key_array,value_array)

key_array-$array

value_array-$array

Creates a new array using the values fromkey_arrayas the keys and the values from

value_arrayas the values.

Note:Returns FALSE if number of entries in both arrays does not match. Example:

$eys = array ( 'na&e'9 'Ro'9 'a*e' );

$"ales = array ( 'Yo'9 'ni*ht'9

? );

$ne%array = arrayDco&ine($eys9 $"ales);

rintDr($ne%array);

rray

(,na&e. ( Yo,Ro. ( ni*ht,a*e. ( ?

See Also:

array_merge() -Combine the keys and values of multiple arrays

array_merge($array [, ...$array...])

Can accept multiple array values, and behaves differently with only one argument

If supplied with only one indexed$array,it reindexes that array continuously.

If supplied with more than one$array,the content of both arrays are combined with

all indexed keys included in the new array, while associative keys that are identical

take the value of the last$arraysupplied.

Example:

76

$array = array ( A = 'one'9 - = 't%o'9 ? = 'three' );

rintDr( arrayD&er*e($array) );

rray

,-.= one,1.= t%o,?.= three

)


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$array = array ( 'Vero'9 'one'9 'na&e' = 'Yo' );

$array? = array ( 'alsoVero'9 'na&e' = 'ohn'9 'Ro' = 'far&er' );

rintDr( arrayD&er*e($array9 $array?) );

( ,-. ( Vero

,1. = one

,na&e. ( ohn

,?. ( alsoVero

,Ro. ( far&er)

See Also:

array_combine()- Combine the values of two arrays into a key=>value array

. . .

If you want to combine two arrays and do not mind if values with the same keys

accept the values from the first array and discard any other arrays supplied, simply

use the plus sign ( + ).

$array = array ( 'Vero'9 'na&e' = 'Yo'9 'Ro' = 'layer' ); $array?

= array ( 'alsoVero'9 'Ro' = 'far&er' );

rintDr( $array @ $array? );

rray

(,-. ( Vero,na&e. ( Yo,Ro. (layer

)

___________________________________________________________________________

array_count_values($array)

Returns an array with the unique values in$arrayas the keys and their count as the

values.

Note:Does not work for multi-dimensional arrays.

Example:

$array = array ( 'Vero'9 'one'9 'Vero' );rintDr( arrayDcontD"ales($array) );

rray

(

,Vero. ( ?,one. ( 1)

See Also:

count()- Count the total number of entries in an array

77


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count($array [,mode])

mode- [optional]$integerdefault:0, does not count multidimensional arrays Othervalue: 1, counts entries within multidimensional arrays

Counts the number of elements in$array.By default, entries within arrays that are

part of$array(multidimensional arrays) are not counted unlessmodeis set to 1.

Examples:

$array = array ('Vero'9

'na&es' = array ( 'Rohn'9 'cla"e' )9

'a*es' = array ( ??9 A ) );

echo cont($array);

A

echo cont($array9 1);

See Also:

array_count_values()- Get the number of unique values inside of an array

array_diff(first_array, $array [, ...$array...])

Accepts multiple $array for comparison against first_array

first_array-$array

Compares the values of all$array(s) against the values infirst_arrayand returns an

array with the entries offirst_arraywhich do not share values with entries in$array(s).

Example:$array = array( 'one'9 't%o'9 'three'9 'for' );

$array? = array( 't%o'9 'three' ); $arrayA = array(

'o' = 'one' );

// "ale is 'one'9 &atchin* $array

rintDr( arrayDdiff($array9 $array?9 $arrayA) );

rray ( ,A. = for )

See Also:

array_diff_key()- Same comparison, but based on keys instead of values

array_diff_assoc()- Same comparison, but based on both keys and values

array_intersect()- Similar, but returns entries that are present in all$array(s)

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array_diff_key(first_array,$array [, ...$array...])

Accepts multiple$arrayfor comparison against first_array

first_array-$array

Compares the keys of all$array(s) against the keys infirst_arrayand returns an array

with the entries offirst_arraywhich do not share keys with entries in$array(s).

Example:

$array = $array? =

rintDr(

rray ( ,na&e. = Rohn )

See Also:

array_diff()- Same comparison, but based on values onlyarray_diff_assoc()- Same

comparison, but based on both keys and values

array_diff_assoc(first_array,$array [, ...$array...])

Accepts multiple$arrayfor comparison against first_array first_array-

$array

Compares the contents of all$array(s) against the keys and values infirst_arrayand

returns an array with the entries offirst_arraywhich do not share exact keys andvalues with entries in$array(s).

Example:

$array = array( 'Vero'9 'one'9 'na&e' = 'Rohn' ); $array?

= array( 'Vero'9 'alsoone'9 'na&e' = 'Rohn' );

rintDr( arrayDdiffDassoc($array9 $array?) );

rray ( ,1. = one )

See Also:

array_diff_key()- Same comparison, but based on keys instead of valuesarray_diff()-

Same comparison, but based on values only

array_intersect(first_array,$array [, ...$array...])

Accepts multiple$arrayfor comparison against first_array first_array-

$array

Compares the values of all$array(s) against the values infirst_arrayand returns an

array with the entries offirst_arraywhich share values with entries from all$array(s).

79

array( 'Vero'9 'na&e' = 'Rohn'9 'Ro' = 'Rohn' );array( 'alsoVero'9 'Ro' = 'Rohn' );

arrayDdiffDey($array9 $array?));


80/176

Example:

$array = array( 'one'9 't%o');

$array? = array( 't%o'9 'one'9 'three'9 'for' ); // 'oneyy

19't%o' &atch

$arrayA = array( 'o' = 'one' );

// only 'one' &atches rintDr( arrayDintersect($array9

$array?9 $arrayA) );

rray ( ,-. = one )

See Also:

array_intersect_key() -Same comparison, but based on keysarray_intersect_assoc() -

Same comparison, but based on both keys and values

array_diff() -Similar, but returns entries that are not present in$array(s)

array_intersect_key(first_array,$array [, ...$array.

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