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TABLE OF CONTENTS

Java Script:................................................................................................................................................3

JavaScript name terminology:..............................................................................................................4

ECMA script:.........................................................................................................4

DOM level 0:.........................................................................................................5

Layers DOM:.........................................................................................................5

Proprietary DOM:..................................................................................................5

W3C DOM:............................................................................................................5

Mocha:..................................................................................................................5

LiveWire:..............................................................................................................5

LiveScript:.............................................................................................................5

 JavaScript:............................................................................................................5

 JavaScript1.0:.......................................................................................................6

 JavaScript1.1:.......................................................................................................6

 JavaScript1.2:.......................................................................................................6

 JavaScript1.3:.......................................................................................................6

 JavaScript1.4:.......................................................................................................6

 JavaScript1.5:.......................................................................................................6

 JavaScript2.0:.......................................................................................................6

 Jscript:..................................................................................................................6

Active scripting:....................................................................................................6

 JellyScript:.............................................................................................................6

InScript:................................................................................................................6

ECMAscript Mobile Profile:....................................................................................7

JavaScript family tree:..............................................................................................................................7

P.T.O......................................................................................................................................................... .7

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Lexical units:..............................................................................................................................................9

Identifiers:..............................................................................................................................................9

Identifier Rule:......................................................................................................9

Examples:2121212121212121212121212121212121212121212121212121212121212121212121212121212121212121212121212121212121212121212121

2121212121212121212121212121212121212121212121.................................9

Keywords:....................................................................................................................................... .....10

Keywords rule:....................................................................................................10

Examples:...........................................................................................................10

case:

...........................................................................................................................10

Reserved words:...................................................................................................................................14

Reserved words rules:........................................................................................15

Examples :..........................................................................................................15

export.................................................................................................................15

Syntax................................................................................................................15

Description.........................................................................................................15

import.................................................................................................................16

Syntax ...............................................................................................................16

Parameters ........................................................................................................16

Description ........................................................................................................16

Literals :..............................................................................................................................................17

Examples:...........................................................................................................17

Integer literals rules...........................................................................................17

Floating Point Literals rules................................................................................17

Boolean Literals..................................................................................................18

String Literals rules.............................................................................................18

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Operators..................................................................................................................................... ........18

Examples:...........................................................................................................19

Arithmetic...........................................................................................................19

Assignment.........................................................................................................20

Comparison........................................................................................................20

Logical................................................................................................................21

String..................................................................................................................21

Examples............................................................................................................21

Comments:...........................................................................................................................................21

Creating Single Line Comments.........................................................................21

Examples:...........................................................................................................21

Display:...............................................................................................................22

Creating Multi-line Comments............................................................................22

Display:...............................................................................................................22

References:...............................................................................................................................................23

Java Script:

JavaScript is considered to be one of the most powerful scripting languages in use today. It is

often used for the development of client-side web development.[1] JavaScript is a prototype-based 

scripting language that is dynamic, weakly typed and has first-class functions. It is a multi-paradigm 

language, supporting object-oriented, imperative, and functional   programming styles. JavaScript was

formalized in the ECMA Script language standard and is primarily used in the form of  client-side

JavaScript, implemented as part of a Web browser  in order to provide enhanced user interfaces and

dynamic websites. This enables programmatic access to computational objects within a host environment.

[2] JavaScript is one of the most well-known trademarks in the web development world; it is the

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trademark of Sun Microsystems. It was originally invented by Netscape and was kept under license for 

some time but now you are not required to get a license in order to use JavaScript. [1]

History:

When the World Wide Web was first created in the early 1990s all web pages were static. When

we viewed a web page we saw exactly what the page was set up to show us and there was no way for us

to interact with the page. So for the interaction with the web page there is need to something in response

to users action required the addition of some form of programming language to instruct the page. So that’s

why Netscape was the first to introduce a programming language for that purpose that allow web pages to

 become interactive—called LiveScript later named as javaScript.[3] JavaScript was originally developed

 by Brendan Eich of Netscape under the name Mocha, which was later renamed to  LiveScript , and finally

to JavaScript mainly because it was more influenced by the Java programming language.[10][11] LiveScript

was the official name for the language when it first shipped in beta releases of Netscape Navigator 2.0 in

September 1995, but it was renamed JavaScript in a joint announcement with Sun Microsystems on

December 4, 1995,[12] when it was deployed in the Netscape browser version 2.0B3. [2] The change of 

name from LiveScript to JavaScript roughly coincided with Netscape adding support for Java technology

in its Netscape Navigator web browser. The final choice of name caused confusion, giving the impression

that the language was a spin-off of the Java programming language, and the choice has been characterized

 by many as a marketing ploy by Netscape to give JavaScript the cachet of what was then the hot new

web-programming language.[14][15] It has also been claimed that the language's name is the result of a co-

marketing deal between Netscape and Sun, in exchange for Netscape bundling Sun's Java runtime with its

then-dominant browser .

In November 1996, Netscape announced that it had submitted JavaScript to Ecma International for 

consideration as an industry standard, and subsequent work resulted in the standardized version named

ECMAScript. [2]

JavaScript name terminology:

The hierarchy and evolution of javaScript name terminology is given below:

These names are subject to interpretation by the browser developers. For example, browsers may

support what they call JavaScript1.5, but not even support DHTML. This makes the JavaScript version

unreliable, do not rely on it.

ECMA script:

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The core syntax for JavaScript, defining control structures, intrinsic objects and variable types,

operators, functions, scope, etc.

DOM level 0:

Says how to refer to forms, inputs, images, links and anchors as children of the document object.

Layers DOM:

Says how to refer to positioned elements (layers) and modify their style as children of the

document object with nested references.

Proprietary DOM:

Says how to refer to elements and modify their style using the all collection of the document or 

 parent object and the style child object of the element.

W3C DOM:

Says how to refer to elements and modify their style using various getElementBy... methods of the

document  or parent object and the  style child object of the element. Also says how to represent all

document elements as a tree structure. Also allows elements to be created, modified or deleted even after 

the document has loaded.

Mocha:

An early name for JavaScript, not recognised by most browsers.

LiveWire:

An early name for JavaScript, not recognised by most browsers, used as the name of Netscape's

server side JavaScript.

LiveScript:

An early name for JavaScript, recognised by most browsers.

JavaScript:

A collective name for all versions of JavaScript.

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JavaScript1.0:

The first version of JavaScript to be released - Early ECMAscript + DOM level 0 without images.

JavaScript1.1:

Early ECMAscript + DOM level 0.

JavaScript1.2:

ECMAscript + DOM level 0 + layers or proprietary DOM.

JavaScript1.3:

More advanced ECMAscript + DOM level 0 + layers or proprietary DOM.

JavaScript1.4:

Server side JavaScript.

JavaScript1.5:

Even more advanced ECMAscript + DOM level 0 + W3C DOM.

JavaScript2.0:

JavaScript 1.5 with several extensions added by Mozilla - may become a future standard.

Jscript:

Microsoft's JavaScript variations with extended core features.

Active scripting:

Microsoft's user friendly way of saying 'JScript'.

JellyScript:

WebTV's interpretation of JavaScript.

InScript:

iCab 3-'s interpretation of JavaScript.

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ECMAscript Mobile Profile:

Parts of ECMAScript, basic JavaScript APIs, and DOM, all mixed together in a single

specification. Incompatible in far too many ways with existing pages on the Web, current browsers, the

ECMAScript specification, the DOM specifications, the JavaScript documentation, and other wellestablished practices. ECMAScript Mobile Profile should be ignored. It is harmful to the Web because of 

its incompatibilities. [4]

JavaScript family tree:

P.T.O

FORTRAN (November 1954)

FORTRAN I (October 1956)

IAL (1958)

ALGOL 60 (1960)

CPL (1963)

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Simula I (1964)

Simula 67 (1967) BCPL (July 1967)

B (1969)

C (1971)

C (K & R) 1978

C with classes (April 1980) Classic C

C++ (July 1983) ANSI C (C 89) 1989

ARM C++ (1989) ISO C (C 90) December 15, 1990

Cmm (1992)

LiveScript (1995)

JavaScript (December 1995)

JavaScript 1.5

JavaScript 2.0 (draft 1) February

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18, 1999

JavaScript 2.0 (draft 4) April 26, 2002

Lexical units:

Identifiers:

JavaScript Identifiers are used to name the JavaScript language entities like variable, object,

function and to provide labels for certain loops in JavaScript code.

Identifier Rule:

A JavaScript identifier or name must start with a letter or underscore ("_"); subsequent characters

can also be digits (0-9). Letters include the characters "A" through "Z" (uppercase) and the characters "a"

through "z" (lowercase). JavaScript is case-sensitive. With some versions of JavaScript, dollar signs are

not legal in identifiers. The best practice of defining JavaScript Identifiers is to avoid the use of dollar 

signs. You can’t use JavaScript reserved keywords as a JavaScript Identifiers.

Examples:

o  Number_hits

o temp99

o  _name

o MyVar 

Different types of java script identifiers are:

var intNum = 82var PI = 3.14

var strInfo="This is a string"

var strGreet=‘Hello!’;

var isMale=true 

var arrAnimal={"cat","dog"}

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Keywords:

Keywords rule:

Keywords are reserved and cannot be used as variable or function names. Here is the completelist of JavaScript keywords:

 break  for  This

case function True

continue if  Typeof 

default Import var 

Delete In Void

do  New while

else  Null with

Export returnFalse switch

 

The underlined keywords are mostly used.

Examples:

break :

Break from executing the current loop, if more than one, break stops execution of the innermost

loop, handing control back to the next innermost. This example code never allows the value of x to exceed8, despite the loop being able to run to 14.

x=0;

while (x<=14) {

if (x==8) {break;}

x++;

}

case:

Case is a keyword used to label compound statements within a switch statement.

switch (x) {

case 1 : {y=x;break;}

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case 2 : {y=x;}

case 3 :

case 4 : {y=x;break;}

default : {y=0;break;}

}

 Note that if x equals 2 or 3, the switch statement continues execution on to the case 4: statement where the

 break statement stops further execution.

Continue :

Continue is used to restart the innermost loop.

x=1; y=1;

while (x<10) {

y++;

if (y==3) break;

else continue;

x++;

}

In this example, the x++ statement is never executed. At the end of the loop, x remains equal to one and y

is incremented to 3, at which point the loop reaches break before the continue can be executed. Note that

as x is never incremented, the loop must exit using break as the condition while (x<10) will never be met

and the loop becomes infinite - your Javascript program will be terminated.

default :

default is a keyword used in a switch statement usually as the last in a series of case statements.

The default case only executes if no case statement matches the value of the expression in the switch

statement.

do

JavaScript 1.2 only:

Use do to extend the function of the while loop. By default while doesn't execute any code within

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the loop unless the while condition evaluates to true. If you need the code to execute ONCE even if the

while condition doesn't (yet) evaluate to true, use do to enclose the code:

x=1; y=1;do {

y++;

if (y==3) break;

else continue;

x++;

}

while (x<10);

for :

Simple loops can use for to save code by initializing, testing and incrementing the test conditions

in one statement:for (initialize ; test ; increment) {}

for (x=0;x<10;x++) {}

The loop executes repeatedly until the test condition evaluates to true. Initialization code is executed once

 before the first evaluation of the test or the loop. The test condition is evaluated before each loop is

executed and the increment expression is executed only once the loop has completed (i.e. just before the

next test condition evaluation).

function

Functions are a way of executing compound statements in one HTML or Javascript call with the

extra flexibility of passing variables to the function.

function my_func(x,y,z) {

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a=x+y-z;

alert(a);

}

This function can be called from HTML as:

<a href="javascript:my_func(10,2,3);">Test</a>

In this example, the alert box should show the result as 9.

if and else

Use if when a simple or compound statement must only be executed if certain variables are

already set to compatible values. The simplest if statement may be a test for division by zero:

a=4;

if (x!=0) {y=a/x;}

else :

Use else to catch instances where the preceding if test condition failed. else cannot be used except

immediately after the closing } of a valid if statement. In situations where if statements are nested inside

other if statements, the else statement will apply to if statement immediately preceding. Take care to put

your else statements beneath the correct} bracket.

a=4;

if (x!=0) {y=a/x;}

else { alert( "Division by zero attempted!" ); }

return:

Use return to stop execution of the current function and return control to the calling

function/procedure.

function my_func(x,y) {

return (x+y);

}

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var sum = my_func(4,8);

In this example, the alert box should show the result as 12.

var :

Each variable in a function must be declared using var and optionally, var can be used to initialise

the variable. Variables defined outside functions can be declared without var.

x=0;

function my_func(x) {

var y=4;

x+=y;

}

while:

Simple loops can use while when the variable is already initialized but the contents of the while

loop must increment or update the variable(s) in the test condition.

var x=0;

while (x<10) {x++;}

The loop executes repeatedly until the test condition evaluates to false. The test condition is evaluated

 before each loop is executed. Note the difference between for and while test conditions, for loops execute

until the test condition is true. while loops execute until the test condition is false.

Reserved words:

Reserved words for future use

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Catch finally

Class super  

Const Throw

Debugger Try

enum importextends export

Reserved words rules:

A reserved word cannot be used

• As a name in literal object notation

•

As a member name in dot notation• As a function argument

• As a var 

• As an unqualified global variable

• As a statement label

Examples :

export

Syntax

export name1, name2, ..., nameN ;

export *;

Parameters

nameN  

Property, function, or object to be exported.

Description

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Typically, information in a signed script is available only to scripts signed by the same principals.

By exporting properties, functions, or objects, a signed script makes this information available to any

script (signed or unsigned). The receiving script uses the companion import statement to access the

information.

The first syntax exports the specified properties, functions, and objects.

The second syntax exports all properties, functions, and objects from the script.

import

Syntax

import objectName.name1, objectName.name2, ..., objectName.nameN ;

import objectName.*;

Parameters

objectName

 Name of the object that will receive the imported names.

nameN

Property, function, or object to be imported.

Description

The objectName parameter is the name of the object that will receive the imported names. For 

example, if f and p have been exported, and if obj is an object from the importing script, the following

code makes f and p accessible in the importing script as properties of obj.

import obj.f, obj.p;

The first syntax imports the specified properties, functions, and objects from the exported script.

The second syntax imports all properties, functions, and objects from the exported script.

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Literals :

JavaScript Literals are the notation for representing a fixed data value that appears directly in a

JavaScript program. JavaScript Literals helps us to assign values (initialize) to various JavaScript Data

Types and Variables; such as integers, floating-point numbers, strings, and Booleans; enumerated Data

Types and compound values such as arrays, records, and objects.

var intNum = 82  // 82 is a integer literal 

var PI = 3.14  // 3.14 is a float literal 

var strInfo="This is a string" // this is a string literal 

var strGreet=‘Hello!’;  // another string literal 

var isMale=true   // A Boolean value literal 

var arrAnimal={"cat","dog"}  // array literals

Examples:

Integer literals rules

Integers can be expressed in decimal (base 10), hexadecimal (base 16), or octal (base 8) format. A

decimal integer literal consists of a sequence of digits (optionally suffixed as described below) without a

leading 0 (zero).

An integer can be expressed in octal or hexadecimal rather than decimal. A leading 0 (zero) on an integer 

literal means it is in octal; a leading 0x (or 0X) means hexadecimal. Hexadecimal integers can include

digits (0-9) and the letters a-f and A-F. Octal integers can include only the digits 0-7.

Some examples of integer literals are:

0, 117 and -345 (decimal, base 10)

015, 0001 and -077 (octal, base 8)

0x1123, 0x00111 and -0xF1A7 (hexadecimal, "hex" or base 16)

Floating Point Literals rules

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A floating-point literal can have the following parts:

• A decimal integer which can be signed (preceded by "+" or "-"),

• A decimal point ("."),

• A fraction (another decimal number),

• An exponent.

The exponent part is an "e" or "E" followed by an integer, which can be signed (preceded by "+" or "-").

A floating-point literal must have at least one digit and either a decimal point or "e" (or "E").

Some examples of floating point literals are:

• 3.1415

• -3.1E12

• .1e12

• 2E-12

Boolean Literals

The boolean type has two literal values: true and false.

String Literals rules

A string literal is zero or more characters enclosed in double (") or single (') quotes. A string must

 be delimited by quotes of the same type; that is, either both single quotes and double quotes. The

following are examples of string literals:

• "blah"

• 'blah'

• "1234"

•

"one line \n another line"

Operators

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The '+' operator is overloaded: it is used for string concatenation and arithmetic addition. This

may cause problems when inadvertently mixing strings and numbers. As a unary operator, it can convert a

numeric string to a number.

Examples:

// Concatenate 2 strings

alert('He' + 'llo'); // displays Hello

 // Add two numbers

alert(2 + 6); // displays 8

 // Adding a number and a string results in concatenation

alert(2 + '2'); // displays 22

alert('$' + 3 + 4); // displays $34, but $7 may have been expected

alert('$' + (3 + 4)); // displays $7 // Convert a string to a number

alert(+'2' === 2); // displays true

JavaScript language supports following type of operators.

Arithmetic

JavaScript supports the following binary arithmetic operators:

+ Addition

- Subtraction

* Multiplication

/ Division (returns a floating-point value)

% Modulus (returns the integer remainder)

JavaScript supports the following unary arithmetic operators:

+ Unary conversion of string to number 

- Unary negation (reverses the sign)

++ Increment (can be prefix or postfix)

-- Decrement (can be prefix or postfix)

var x = 1;

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alert(++x); // displays: 2

alert(x++); // displays: 2; x becomes 3 then

alert(x); // displays: 3

alert(x); // displays: 2

alert(--x); // displays: 1

Assignment

= Assign

+= Add and assign

-= Subtract and assign

*= Multiply and assign

/= Divide and assign

%= Modulus and assign

Assignment of primitive types

var x = 1;

x *= 3;

alert(x); // displays: 3

x /= 3;

alert(x); // displays: 1

x -= 1;

alert(x); // displays: 0

Comparison

== Equal

!= Not equal

> Greater than

>= Greater than or equal to

< Less than

<= Less than or equal to

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=== Identical (equal and of the same type)

!== Not identical

Logical

JavaScript provides four logical operators:

• unary negation (NOT = !a)

•  binary disjunction (OR = a || b) and conjunction (AND = a && b)

• ternary conditional (c ? t : f)

String

= Assignment

+ Concatenation

+= Concatenate and assign

Examples

str = "ab" + "cd"; // "abcd"

str += "e"; // "abcde"

str2 = "2"+2 // "22", not "4" or 4.

Comments:

Creating Single Line Comments

To create a single line comment in JavaScript, you place two slashes "//" in front of the code or 

text you wish to have the JavaScript interpreter ignore. When you place these two slashes, all text to the

right of them will be ignored, until the next line.

These types of comments are great for commenting out single lines of code and writing small notes.

Examples:

<script type="text/javascript">

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<!--

// This is a single line JavaScript comment

document.write("I have comments in my JavaScript code!");

//document.write("You can't see this!");

//-->

</script>

Display:

I have comments in my JavaScript code!

Creating Multi-line Comments

Although a single line comment is quite useful, it can sometimes be burdensome to use when

disabling long segments of code or inserting long-winded comments. For this large comments you can use

JavaScript's multi-line comment that begins with /* and ends with */.

<script type="text/javascript">

<!--

document.write("I have multi-line comments!");/*document.write("You can't see this!");

document.write("You can't see this!");

document.write("You can't see this!");

document.write("You can't see this!");

document.write("You can't see this!");

document.write("You can't see this!");

document.write("You can't see this!");*/

//-->

</script>

Display:

I have multi-line comments! [5,6,7,8,9]

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References:

[1] http://www.webopedia.com/TERM/J/Javascript.html

[2] http://en.wikipedia.org/wiki/JavaScript

[3] http://javascript.about.com/od/reference/a/history.htm

[4] http://www.howtocreate.co.uk/jshistory.html

[5] https://developer.mozilla.org/en/JavaScript/Reference/Reserved_Words

[6] http://www.hscripts.com/tutorials/javascript/numbers.php

[7] http://www.codehelp.co.uk/html/jscript1.html

[8] http://www.tutorialspoint.com/javascript/javascript_operators.htm

[9] http://en.wikipedia.org/wiki/JavaScript_syntax#Operators

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