c Language by SRIDHAR

7/28/2019 c Language by SRIDHAR

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** 'C'

=> Programming Language

=> Middle Level Language

=> Case Sensitive Language

(Recognisation of upper and lower case

alphabets will be different)

ASCII Values

(American Standard Code for Information Interchange)

0 to 255

Software:

"Set of related Programs"

1. Operating Systems

"Acts as an interface media between the user and the system"

2. Packages

"Readymade set of programs"

Ex: MS office

3. Languages

" No readymade programs, instead we

have to create our own programs"

Ex: 'C'

Language:

"Communication media"

Binary / Machine Language( 0's & 1's)

=> Programming Languages:

These are used as media by the programmer to interact / instruct the system.


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1. Low Level Languages

=> Easy only for machines

Ex: Assembly Language

2. Middle Level Languages

=> Easy for both -> interface between low & High

Ex: 'C' Language

3. High Level Languages

=> Easy only for human beings

Ex: BASIC, COBOL, PASCAL, C++, JAVA

=> 'C' Character Set:

=> Alphabets 1. Upper Case (A to Z)

2. Lower Case (a to z)

=> Numerals / Digits 0 to 9

=> Special Characters

1. Simple Keys

+ - * / | _ " ; : ' ? \ > < , . # % ^ & ! ~

( ) { } [ ] = .....

2. Compound/Meta Keys

>= > ....


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Words:

"Grouping up of characters,

to convey some meaning"

1. Reserved Words(Keywords)

2. User Defined Words(Identifiers)

Software

|

Set of related program

|

Set of ordered instructions/Statements

|

Grouping up of Expressions

|

Combination of Constants, Operators, Operands,

Keywords, Function Calls, etc.

(Collection of Tokens)

Tokens (Building Blocks)

It is a small individual unit used in a program

1. Keywords

2. Identifiers

3. Literals


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4. Operators

5. Punctuators

1. Keywords (Reserved Words):

These are the pre-defined words of the language assigned with unique meanings or operations.

'C' consists of totally 32 keywords (ANSI-C -> 36 keywords).

int signed enum break

char unsigned extern continue

float static register goto

double include auto switch

long define if case

short typedef else default

return FILE

while EOF

for volatile

do void

struct const

union sizeof

Variable:\

It is an entity (memory container) that holds the data stored

Ex:

2. Identifiers:


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These are the user-defined words / labels defined for giving identity to different entities used in

a program, such as variable names, function names, file names, fieldnames, typenames, etc.

=> Conventions for framing identifiers:

1.Should begin with an alphabet followed by numerals may also be used.

2. No special characters except under score ( _ ) is allowed

3. Should be short, easy and meaningful.

4. Should be unique i.e. non-similar

5. Keywords should not be used as Identifiers

6. Recognisation of Upper case and Lower case alphabets will be different

7. It can be of maximum 40 characters long in length

3. Literals:

These are the constants that remains unchanged throughout the program execution.

'C' classifies the literals into the following five types:

i. Character Literals => Enclosure of single key within

single quotations

Ex: 'A' , '6', '#', '\n'

ii. String Literals => Enclosure of group of characters

within double quotations

Ex: "Satyam", "123"

iii. Integral Literals=> Rep. a numerical value without

decimal fraction

Ex: 250 , -32768

iv. Floating Literals => Rep. a numerical value with

decimal fraction

Ex: 3.14159 , -124.3657

v. Logical / Boolean Literals => Rep boolean values i.e. in the

form of true (1) / false (0)

Ex: 10>20 => 0


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4. Operators:

These are the special characters (symbols) which are assigned

with unique operations to be executed when used along with operands.

C has rich set of built-in operators, which are categorized into two classifications:

1. Unary Operators: Used along with single operand

Ex: ++ -- & - ! ~

2. Binary Operators: Used along with two operands

Ex: + - * / % < > = ...

In C, operators are divided into different types, depending on the type of operations they

perform:

1. Arithmetical Operators: Used for mathematical calculations

+ (plus) => Addition a + b

- (minus)=> Subtraction x - y

* (Asterisk) => Multiplication r * m

/ (Slash) => Division a / b

% (Percent) => Modular Value (Remainder) x % z

2. Relational Operators: Used for making comparision between

two similar type of data items

> => Greater than

< => Less than

>= => Greater than or Equals to

Less than or Equals to

== => Equals to


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!= => Not Equals to

3. Logical Operators: Used for joining two conditions as single

And ( && ) => all must be satisfied

Or ( || ) => Either one should be satisfied

Not ( ! ) => Neither should be satisfied

4. Bitwise Operators: Used to manipulate the data in the form of bits

~ (Tilda) => One's Compliment

Shift Left

>> => Shift Right

& (Ambersent) => Bitwise AND

| (Pipe) => Bitwise OR

^ (Carrot) => Bitwise Exclusive OR (XOR)

5. Assignment Operators: Used for assigning RHS into LHS operands

= => Assigns RHS into LHS

Ex: c=a+b;

+= => Adds RHS into LHS Operand

Ex: x=x+10; -> x+=10;

-= => Substract RHS from LHS

Ex: r=r-5; -> r-=5;

*= => Multiplies RHS with LHS

Ex: a=a*10; -> a*=10;


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/= => Divides LHS by RHS

Ex: m=m/2; -> m/=2;

%= => Modularizes LHS mod RHS

Ex: g=g%2; -> g%=2;

5. Punctuators:

These are the special characters used for grouping or ungrouping the elements of a program.

i. { } => Braces

-> Used for grouping set of statements as a single block

->

->

ii. ( ) => Paranthesis

-> Used for giving or representing the data for the functions

->Used for representing higher priority in evaluation of an expression

iii. [ ] => Brackets

->

->

iv. ; => Semi Colon -> Used as statement terminator

->

v. , => Comma

-> Used as separator between the elements of a program


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->

vi. . => Decimal Period

->

vii. # => Hash

-> Used for including the required header files

-> Also used for defining constant identifiers

Data Types

Classification of the data into different types depending on the type of keys used in framing the

data, for exact memory allocation and faster memory access.

1. Primitive Data Types:

These are pre-defined data types of C language

1. int :

=> It is used for storing numerical value without decimal fraction

=> It only allows numerals from 0 to 9

=> It also allows two special characters + and -

=> It is one word in length

=> It occupies two bytes (16 bits) of memory

=> It's value ranges between -32768 to 32767

Ex: 256, -4576, +226

2. char :

=> It is used for storing any single key / character

=> It is one word in length


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=> It holds the ASCII value of the given character

=> It occupies one byte (8 bits) of memory

=> It's value ranges between -128 to 127

Ex: A -> 65, 8 -> 56, #

3. float :

=> It is used for storing numerical value with decimal fraction

=> It allows numerals from 0 to 9

=> It also allows three special characters i.e.

+, - and decimal ( . )

=> It is two words in length

=> By default it takes 6 decimal digits

=> It occupies 4 bytes (32 bits) of memory

=> It's value ranges between 3.4E-38 to 3.4E+38

Ex: 123.5774, -2458.33

4. double:

=> It is used for storing numerical value with

decimal fraction

=> It allows numerals from 0 to 9

=> It also allows three special characters i.e.

+, - and decimal ( . )

=> It is two words in length

=> By default it takes 8 decimal digits

=> It occupies 8 bytes (64 bits) of memory

=> It's value ranges between 1.7E-308 to 1.7E+308

5. void:


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=> It is blank i.e. no data so no memory allocation

=> It is used in function as return data type.

Expressions:

It is combination of constants, operators, operands, punctuators, function calls, keywords, etc.,

which when executed returns any value/data.

In 'C', expressions are classified into five types depending on the type of data it returns.

1. Character Expressions (< ExpC >):

Ex: toupper('a')

2. String Expressions (< ExpS >):

Ex: "abc" + "def"

3. Integral Expressions (< ExpN >):

Ex: a+20, 25/10=>2

4. Floating Expressions (< ExpN >):

Ex: 3.14159*r*r

5. Logical / Boolean Expression (< ExpL >):

Ex: a>b => 1/0

Statements:

"Grouping up of expressions according to the symantic rules of 'C' language, which when

executed performs an act or an operation.

In 'C', statements are of the following categories:

1. Comment-entry statements

2. Input Statements

3. Output Statements


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4. Declaration Statements

i. Variable Declarations

a. Local Declarations

b. Global Declarations

ii. Structure Declarations

iii. Type definitions

5. Pre-processor directive Statements

6. Control Structures

i. Branching Statements

a. goto

b. continue

c. return

d. break

ii. Conditional Statements

a. if

b. if else

c. switch statements

iii. Loop / Iterative Controls

a. while statement

b. for statement

c. do while statement

d. True / Continuous Statement

7. Null Statements

8. Definition Statements, etc.


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=> Evolution of Programming Languages:

Binary Language ( 0's & 1's)

|

Assembly Language (Low-Level Language)

|

High Level Languages

||

Procedure Oriented Programming (POP)

(Emphasis is on task)

||

Object Oriented Programming (OOP)

(Emphasis is on data)

=>Structure of 'C' Program:

[ Descriptive / Comment-Entry Statements (Documentation Section) ]

Pre-Processor Directive Statement ( Linkage Section )

[ Global Declarations / Definitions ]

Body

[1. Local Declaration Statements ]

2. Executable Statements

Syntax:

main ( )

{

[Declaration Statements;]


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Executable Statements;

}

[Function1 ( )

{

Declaration Statements;

Executable Statements;

}

..

..

..]

=>Descriptive / Comment-Entry Statements:

These are non-executable and optional statements (Compulsory to be used) that are used for

giving description about the current program, such as purpose, environment used, date and time of

program creation, name of the programmer and so on.

These statements can appear any where in the program for any number of times.

Syntax:

1. /* Description */

=> Single Line Comment

2. /* Description

Description

Description */

=> Multi Line Comment

Ex:

1. /* Sample C Program */


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2. /* Program to find sum of two numbers

Written by Dennis Ritchie */

=> Pre-processor Directive Statements:

Library Files

(Header Files)

....

These are the statements that are used for including i.e. linking the necessary header file /s

within the current program using "#include" directive, depending on the type of functions we use in the

program.

Syntax:

# include < Header Filename >

Ex:

# include

# include

# include


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These statements are also used for defining constant type of variables with the required

expression, by using "#define" directive

Syntax:

# define

Ex:

# define pi 3.14159

# define size 100

# define Hi "Good Evening"

=>Global Declarations / Definitions: (optional statements)

Statements used for declaration of global version of variables, constants, functions or also used

for defining global version of type definitions, which can be accessed throughout the program and gets

released as soon as the program ends.

-> Declaration of global version of variables:

Syntax:

;

Ex:

int x;

char ch;

float p;

double d;

int a,b,c;

=> Body:

As 'C' is a modular programming language, where a single program can be split into n number of

modules known as functions.

Body is the main function of the C program that gets executed first by C compiler as soon as the

programmer runs the program. To differentiate the body from the other functions, it is given heading as

"main ( )". Beginning and Ending of a block


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are represented by " { " and " } " respectively. Every statement in C should be terminated by " ; ".

Body consists of two types of statements:

1. Declaration Statements

2. Executable Statements

Syntax:

main ( )

{

[Declaration Statements ;]

Executable Statements ;

}

Ex:

main()

{

printf (" Hi, Welcome to the World of Satyam ") ;

}

1. Declaration Statements:

These are used for declaration of local version of variables that can be accessed only within the

main function.

Syntax:

;

2. Executable Statements:

These are the statements that when executed performs an act or an operation, such as takes

input, gives output, checks condition and so on.


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=> Functions: (Self Contained block or program)

It is a module or block of a program, that contains set of statements related to perform a

particular sub task, having a unique identity known as function name.

/* Sample C Program */

#include

main()

{

int a,b,c;

a=10;

b=20;

c=a+b;

printf(" Sum = %d" , c);

}

=> Different C Compilers:

|

These are the translator programmes that are used

for converting the source code into binary code and

vice versa.

=> TC -> Turbo C -> Turbo Corporation

QC -> Quick C -> Micro Soft Corporation

UNIX & C -> A T & T Bell Laboratories

BC -> Borland C -> Borland Corporation


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ANSI - C -> American National Standard Institute

Getting Started with Turbo C programming:

1. Start => Run & type

C:\Tc\Tc.exe => Click on OK button

2. Start => Run & type

Command => Click on OK button

=> CD\

C:\>

=> Type CD TC

C:\TC>

=> Type TC and press enter key

C:\TC> TC

3. Double click on Turbo C Short icon on the Desktop (if exist)

4. Select Start => Programs => Turbo C

=> Press Alt+Enter

Notes:

1. To Save the Program : Alt+F(File) => Save

(Default extension for C files will be ".C") OR Press F2

(Sample . C)

2. To compile the program: Alt+C(Compile)=>Compile OR Alt+F9

(Automatically creates object file with ".OBJ") (Sample.OBJ)

3. To zoom / unzoom the current window: Press F5

4. To toggle between the message window and edit window: Press F6


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5. To run/execute the program: Alt+R(Run)=> Run OR Press Ctrl+F9

(Automatically creates output file with ".EXE") (Sample.Exe)

Source Code =>Compiler => Object Code => Linker => Output Code

(.C) (.OBJ) (.EXE)

6. To toggle between the output window and the editor Alt+F5

7. To write a new program: Alt+F(File)=> New

8. To opening an existing program: Alt+F(File)=> Load OR Press F3

9. To quit the editor: Alt+F(File)=>Quit OR Press Alt+X

/* Sample C Program */

#include

main( )

{

printf(" Hi, Good Morning ") ;

}

=> Output Statements:

These are the statements that gives output to the user by the program.

=> printf ( ): print Formatted

It is the built-in C formatted output function that prints

the output of the given expressions on the monitor in the specified

format. It is defined in file.

Syntax:


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printf ( [ " Format Specifiers " , ] ) ;

Where

Expression => a Constant, an Operand, an operator,

a formula, a function call, a keyword, etc.

Format Specifiers:

These are the codes that are used for representing

the type of data to be taken as input or the type of output to be given by the

program, to C compiler.

"%d" => int

"%c" => char

"%f" => float

"%s" => string

"%l" => long

"%u" => unsigned

"%lf" => double

"%ld" => long int

"%ud" => unsigned int

Ex: 1. printf(" Good Evening ");

2. int x =10 , y = 20;

printf(" %d & %d " , x , y );

=> 10 & 20

3. printf ( " x = %d and y = %d " , x , y ) ;

=> x =10 and y = 20


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4. c = x + y ;

printf ( " Sum = %d " , c ) ;

OR

printf ( " Sum = %d " , x + y ) ;

=> Sum = 30

5. int x =10;

char ch = 'A' ;

float p =123.57888 ;

printf ( " x = %d ch = %c p = %f " , x , ch , p ) ;

=> x = 10 ch = A p = 123.578878

/* To find sum of two nos */

#include

main()

{

int a=40 , b=20;

printf(" Sum = %d " , a+b);

}

=> WAP to find sum, difference, product and division of two nos where

x=50 and y=5

/* To find the area of a circle */

#include

#define pi 3.14159


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main()

{

int r=5;

printf(" Area of a Circle : %f ",pi*r*r);

}

/* To find sum, difference, product and division of two nos */

#include

main()

{

int x=50 , y=5;

printf("\n Sum = %d " , x+y);

printf("\n Difference = %d " , x-y);

printf("\n Product = %d\n",x*y);

printf(" Division = %d " , x/y);

}

-> printf( "\n Sum = %d\n Difference = %d\n Product = %d\n Division = %d ",

x+y , x-y , x*y , x/y);

=> Input Statements:

These are the statements that are used for taking the

necessary input from the user through keyboard.

=> scanf ( ): scan format


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It is a built-in C formatted input function that scans or

gets the required specified type of data as input from the user and

stores them into the given identifiers (variables) address. It is

defined in file.

Syntax:

scanf( " format specifiers " , & );

Where

Identifier => Variable name

& (Ambersent ) => Reference / Address Operator

format specifiers => codes used for rep. the data type

Ex:

1. int a,b;

scanf( "%d%d" , &a , &b );

2. int n;

scanf("%d" , &n);

3. int x;

char ch;

float p;

scanf( "%d%c%f" , &x , &ch , &p ) ;

/* To find sum, difference, product and division of two given nos */

#include

main()

{

int a,b;


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printf("\n Enter two values :");

scanf("%d%d",&a,&b);

printf("\n Sum = %d ",a+b);

printf("\n Difference = %d\n",a-b);

printf(" Product = %d \n",a*b);

printf(" Division = %d ", a/b);

}

/* To find the area of a circle */

#include

main()

{

int r;

printf(" Enter radius of a Circle :");

scanf("%d" , &r);

printf(" Area of Circle = %f " , 3.14159*r*r ) ;

}

=> wap to find the area and perimeter of a rectangle

/* To find the area and perimeter of a rectangle */

#include

main()

{

int l,b; clrscr();

printf(" Enter length and breadth of a rectangle :");


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scanf("%d%d", &l, &b);

printf(" Area of a Rectangle = %d ", l*b);

printf("\n Perimeter of a Rectangle = %d ", 2*(l+b));

}

/* To swap the two given numbers */

#include

main ( )

{

int a , b , c ; => int a , b;

printf(" Enter two numbers :");

scanf( "%d%d" , &a , &b );

printf(" Before swapping values are a=%d and b=%d" , a , b );

c=a; => a=a+b;

a=b; => b=a-b;

b=c; => a=a-b;

printf("\n After swapping values are a=%d and b=%d " , a , b );

}

=> clrscr ( ):

It is a built-in C console function that clears the output window's screen. It is defined in

file

Syntax:

clrscr ( );

'C' Language


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=> Programming Language

=> Middle Level Language

=> Case Sensitive Language

=> Modular / Block Programming

(Large programs can be split into blocks)

1. Easy readability and easy understandability

2. Easy debugging of errors

3. Easy sharing of work

=> Procedure Oriented Programming (POP)

=> Emphasis is on task

=> Large programs are split into functions

=> General Purpose programming

=> Structural programming

-> Syntax & Symantic rules

-> Memory resident programming feature

Definition:

'C' is a general purpose structured modularized procedure

oriented case sensitive middle level programming language, that

acts as an interface between low level and high level languages.

History of C Language:

High-Level Languages (ALGOL) - early 1960's

|

BCPL - Martin Ritchard - early 1964's


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(Basic Combined Programming Language)

|

"B" (BASIC) Language - Ken Thompson - 1967

|

"C" Language - Dennis M Ritchie - 1972

at A T & T Bell Laboratories, Murray Hills,

New Jersy (USA)

|

"C with Classes" - Bjarne Stroustrup - 1982

|

Renamed it as "C++" - 1983

/* To read and print a character */

#include

main ( )

{

char x;

clrscr( );

printf(" Enter an alphabet :");

scanf("%c", &x);

printf(" Given alphabet = %c" , x ) ;

}

=> getchar ( ):

It is a built-in C Character input function that gets or reads a single character / key as input and

assigns it into the left hand side character variable. It is defined in file


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Syntax:

=getchar ( );

Ex:

char m;

m=getchar ( );

=> putchar ( ):

It is a built-in C Character output function that puts or prints the given character expression on

the monitor. It is defined in file.

Syntax:

putchar();

Ex:

1. putchar(m);

2. putchar( 'S' );

=> S

/* To read and print a character using getchar ( ) and putchar ( )*/

#include

main ( )

{

char x;

clrscr( );


x=getchar( );

printf(" Given alphabet = ");

putchar(x);


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}

#include

main()

{

int a , b; clrscr();

printf( " Enter two numbers :");

scanf("%d%d" , &a, &b);

if(a>b)

{

printf(" Biggest = %d " , a);

printf("\n Smallest = %d " , b);

}

else

printf(" Biggest = %d \n Smallest = %d ", b , a);

getch();

}

/* To convert the given upper case alphabet into lower case */

#include

main ( )

{

char ch;

clrscr();


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printf(" Enter an upper case alphabet :");

ch=getchar( );

ch=ch+32;

printf(" Lower case alphabet = %c" ,ch);

}

=> To convert the given lower case alphabet into upper case

=> Conditional / Selection Statements:

Condition:

=> Making comparision between two

similar type of data items

1. Simple Conditions:

Ex: a>b

2. Compound/ Complex Conditions:

Ex: a>b && a>c

These are the statements that are used for decision making within a program

by imposing a condition and performing either executions, i.e. these statements are

used for altering the sequential execution of the program.

i. Simple if

ii. if else

iii. Nested if else / if else if ladder

iv. switch Statement


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i. Simple if:

In this notation we only specify what to be executed when the condition

is true i.e. no alternative execution is specified.

Syntax:

if ()

{

Statement 1;

Statement 2;

...................

Statement n;

}

Ex:

if ( a % 2 == 0 )

{

printf(" Given number is Even ");

}

if( a % 2 != 0 )

{

printf(" Given number is Odd ");

}

ii. if else:

In this notation we specify either executions to be executed depending

on the evaluation of the condition.

Syntax:

if ()


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{

Statement 1;

Statement 2; --> True Block

...................

Statement n;

}

else

{

Statement 1;

Statement 2; --> False Block

....................

Statement n;

}

Ex:

if ( a % 2 == 0)

{

printf(" Given number is Even ");

}

else

{

printf(" Given number is Odd ");

}

/* To find the biggest among the two given numbers */


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#include

main()

{

int x , y; clrscr();


scanf("%d%d" , &x ,&y);

if( x>y )

printf(" Biggest = %d " , x);

if( y>=x ) => else

printf(" Biggest = %d " , y);

getch();

}

=> To find biggest and smallest among two given numbers

=> To find whether the given number is even or odd

/* To find whether the given alphabet is an upper case or lower case alphabet */

#include

main()

{

char x ; clrscr();


x=getchar( );

if( x>=65 && x if ( x>= 'A' && x


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printf(" Given alphabet is of Upper case ");

else

printf(" Given alphabet is of Lower Case ");

getch( );

}

#include

main()

{

int a,b,c; clrscr();

printf(" Enter three numbers :");

scanf("%d%d%d", &a,&b,&c);

/* Compound Conditions */

if(a>b && a>c)

printf(" Biggest = %d ",a);

else

if(b>c)

printf(" Biggest = %d ",b);

else

printf(" Biggest = %d ",c);

if(a


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printf("\n Smallest = %d ",b);

else

printf("\n Smallest = %d ", c);

getch();

}

=> Character Functions:

These are the functions that are used for manipulation of the character type

of data. These functions are defined in file.

1. toupper ( ):

->Returns the converted given character expression from lower case to upper case.

Syntax: ( x - 32 )

toupper();

Ex:

1. x = toupper( x ) ;

2. toupper( 'b' );

=> B

2. tolower( ):

-> Returns the converted character of the given character expression from

upper case to lower case.

Syntax: ( x + 32 )

tolower()

Ex:


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1. ch = tolower( ch );

2. tolower( 'G' ) ;

-> g

3. isupper( ):

-> Used for checking whether the given character expression is representing

an upper case alphabet or not. If yes return 1 (true) otherwise returns 0 (false).

Syntax: ( x >= 65 && x 0

4. islower( ):


an lower case alphabet or not. If yes return 1 (true) otherwise returns 0 (false).

Syntax: (x >= 97 && x


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2. islower( 'j' )

-> 1

5. isalpha( ):


an alphabet or not. If yes return 1 (true) otherwise returns 0 (false).

Syntax: ( (x >= 65 && x =97 && x 0

6. isdigit( ):


a digit or not. If yes return 1 (true) otherwise returns 0 (false).

Syntax: (x >= '0' && x < = '9' )

isdigit ()

Ex:

1. if( isdigit(x) )

printf(" Given character is a digit ");

else

printf(" Given character is not a digit");

2. isdigit( 'j' )


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-> 0

7. isspace( ):


a space or not. If yes return 1 (true) otherwise returns 0 (false).

Syntax: (x==' ')

isspace ()

Ex:

1. if( isspace (x) )

printf(" Given character is a space ");

else

printf(" Given character is not a space");

2. isspace( ' ' )

-> 1

=> Write a program to find whether the given character is an alphabet or not

3. Nested Conditional Statements:

-> Grouping or using one or more conditional statements within an

another conditional statement, is referred as Nested Conditional Statements.

Syntax:

if()

if()

{

Statements; -> 1-T & 2-T

}


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else

{

Statements; -> 1-T & 2-F

}

else

if()

{

Statements; -> 1-F & 3-T

}

else

{

Statements; -> 1-F & 3-F

}

/* To find biggest among three given numbers */

/* Simple Conditions */

/* Nested Conditional Statements */

#include

main( )

{

int a , b , c ;

clrscr( );

printf(" Enter three values :");

scanf( "%d%d%d" , &a , &b , &c ) ;


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if(a>b)

if(a>c)

printf(" Biggest = %d",a);

else

printf(" Biggest = %d",c);

else

if(b>c)

printf(" Biggest = %d",b);

else


getch( );

}

=> To find biggest and smallest among three given nos

=> if else if Ladder:

Grouping up of if statements after else part of the conditional statements is referred as if else if

ladder.

Syntax:

if()

{

Statements; -> 1-T

}

else

if()

{


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Statements; -> 1-F & 2-T

}

else

if()

{

Statements; -> 1-F , 2-F & 3-T

}

.....

else

{

Statements; -> No condition is true

}

/* To find biggest among three given numbers */

/* Compound Conditions */

/* if else if Ladder */

#include

main( )

{

int a,b,c;

clrscr( );

printf(" Enter three values :");

scanf("%d%d%d" , &a , &b , &c ) ;

if(a>b && a>c)


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printf(" Biggest = %d",a);

else

if(b>c)

printf(" Biggest = %d",b);

else


getch( );

}

=> Wap to find whether the given number is positive, negative or zero

/* To check whether the given character is an alphabet, a digit, a space or a special

character*/

#include

#include

main( )

{

char x; clrscr( );

printf(" Enter a character :");

x=getchar( );

if( isalpha(x) )

printf(" Given character is an alphabet ");

else

if( isdigit(x) )



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else

if( isspace(x) )

printf(" Given character is a space ");

else

printf(" Given character is a special character ");

getch( );

}

=> Ternary / Conditional Operator ( ?: ):

It is a special built-in 'C' operator that is used for evaluation of the given

condition and perform either action or returns either value.

Syntax: () ? :

Ex:

(a>b) ?a :b

OR

printf(" Biggest = %d" , (a>b) ?a :b );

2. (a>b) ?printf(" Biggest = %d",a); : printf(" Biggest =%d " ,b);

3. (a>b) ? (a>c) ? a : c :(b>c) ? b : c -> Nesting of Ternary Operators

-> Simple Conditions

4. (a>b && a>c) ? a : (b>c) ? b : c -> Compound Conditions

/* To find biggest and smallest among three given numbers using Ternary Operator */

#include

main( )


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{

int x , y , z ; clrscr( );

printf(" Enter three numbers :");

scanf("%d%d%d" , &x , &y , &z );

printf(" Biggest = %d" , (x>y && x>z) ?x :(y>z) ?y :z );

printf("\n Smallest = %d", (x


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printf(" Two");

else

if(n==3)

printf(" Three ");

else

if(n==4)

printf(" Four");

else

if(n==5)

printf(" Five ");

else

if(n==6)

printf(" Six");

else

if(n==7)

printf(" Seven");

else

if(n==8)

printf(" Eight");

else

if(n==9)

printf(" Nine");

else

printf(" Invalid Digit, Try again");

getch();


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}

4. switch Statement:

It is a selection statement that is used for performing one among the given

n number of alternative executions depending on the output yielded by the given

expression.

Syntax:

switch()

{

case :

Statements; break;

case :

Statements; break;

case :

Statements; break;

.....

.....

case :

Statements; break;

default:

Statements;

}

/* To print the given digit in characters using switch statement */

#include

main( )


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{

int n; clrscr( );

printf(" Enter a digit :");

scanf("%d",&n);

switch(n)

{

case 0: printf(" Zero"); break;

case 1: printf(" One "); break;

case 2: printf(" Two"); break;

case 3: printf(" Three"); break;

case 4: printf(" Four"); break;

case 5: printf(" Five"); break;

case 6: printf(" Six"); break;

case 7: printf(" Seven"); break;

case 8: printf(" Eight"); break;

case 9: printf(" Nine"); break;

default: printf(" Invalid digit, try again");

}

getch();

}

/* To check whether the given alphabet is a vowel or a consonent */

#include

main( )

{


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char m;

clrscr( );


m=getchar( );

switch(m)

{

case 'A' :

case 'a' :

case 'E' :

case 'e' :

case 'I' :

case 'i' :

case 'O' :

case 'o' :

case 'U' :

case 'u' : printf(" Given alphabet is a Vowel "); break;

default: printf(" Given alphabet is a Consonent ");

}

getch( );

}

=> Escape Sequence Characters:

These are the codes that are used for formatting the output of a program by

executing the printable characters and printing the executable characters. These

codes should begin with Backward slash ( \ ) followed by a character and should be


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specified within double quotations.

"\a" => Audible Bell (Beep sound)

"\b" => Backspace key

"\r" => Cariage Return

"\t" => horizontal Tab ( 8 spaces)

"\v" => Vertical Tab

"\n" => New line character

"\\" => Prints \ character

"\"" => Prints " character

"\' " => Prints ' character

"\?" => Prints ? character

'\0' => Null Character

Ex: printf("\"Hi, Good evening\" "); => " Hi, Good Evening"

/* To display the address of Satyam institute */

#include

main()

{

clrscr();

printf("\n\n\n\n\n\n\n\n\n\n\t\t\t\t\"SATYAM COMPUTER EDUCATION");

printf("\n\t\t\t #17-7-77, Laxmi Linga Rao Arcade,");

printf("\n\t\t\t 4th Floor, Above Hero Honda Showroom,");

printf("\n\t\t\t\tMankamma Thota, KARIMNAGAR\"");

getch();


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}

=> gotoxy( ):

It is a built-in 'C' function that is used to move the cursor to the specified

position on the screen, where the position is specified in terms of column and row,

where column can be in between 0 to 79 and row can be in between 0 to 23.

Syntax: gotoxy(,);

Ex: gotoxy(25,12);

/* To display the address of Satyam institute */

#include

main()

{

clrscr();

gotoxy(24,10); printf("\"SATYAM COMPUTER EDUCATION");

gotoxy(20,11); printf("#17-7-77, Laxmi Linga Rao Arcade,");

gotoxy(20,12); printf("4th Floor, Above Hero Honda Showroom,");

gotoxy(24,13); printf("Mankamma Thota, KARIMNAGAR\"");

gotoxy(28,9); printf(" N. Kamalakar Rao");

getch();

}

Loop /Iterative Control Statements

These are the statements that are used for repeatation of the given set

of statement's execution for required n number of times.

'C' provides four different types of loop statements, which can also be

referred as Iterative control statements:


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1. while Statement

2. for Statement

3. do while Statement

4. True / Continuous Statement

1. while Statement:

It is a loop / iterative control statement that repeats the execution of the

given set of statements for repeated n number of times, until the given condition is

met or satisfied.

Syntax:

Initialization of Loop Variable;

while() -> Loop Exit Test

{

Statement 1;

Statement 2;

. . . . . . . . . . .

Statement n;

Modification of Loop Variable;

}

Ex:

/* To generate whole numbers from 0 to 20 */

#include

main( )

{

int n=2;


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clrscr( );

while(n=1)

{

printf("\n %d " , n);

n=n-1;

}

getch( );

}

=> To generate even numbers from 2 to 100

=> To generate odd numbers from 99 to 1 and find their total


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/* To generate all ASCII codes and characters in page format */

#include

main( )

{

int n=0;

clrscr( );

while(n


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{

printf("\n %d * %d = %d " , m , n , m*n ) ;

n=n+1;

}

getch( );

}

=> To generate addition table for the given number

/* To generate fibonnacci series below 100 */

#include

main()

{

int a=0 ,b=1; clrscr();

while(b Increment & Decrement Operators:

C has two special built-in operators by name Increment and Decrement operators, which are

denoted as "++" and "--" respectively.


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++ => Increment Operator

-- => Decrement Operator

Ex: n=n+1; --> n++; / ++n;

x=x-1; --> x-- ; / --x;

Increment Operator (++) is used for increasing i.e. raising the given operands

value by one.

Decrement Operator (--) is used for decreasing i.e. reducing the given operands

value by one.

Both the above operators are classified into two types:

1. Pre 2. Post

In Pre-Incrementing / Decrementing, the value of the given operand is first

raised / reduced and later the modified value is used in the given execution.

In Post-Incrementing / Decrementing, the value of the given operand is first

used in the given execution (unmodified) and later it is raised / reduced.

Pre-Increment Post-Increment

Syntax: Syntax:

++; ++;

Ex: Ex:

int x=3,y; int x=3,y;

y=++x; -> x=4 y=x++; ->y=3


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y=4 x=4

Pre-Decrement Post-Decrement

Syntax: Syntax:

--; --;

Ex: Ex:

int m,n=7; int m,n=7;

m=--n; m=n--;

-> n=6 m=7

m=6 n=6

/* To generate whole numbers from 20 to 0 */

#include

main( )

{

int n=20; clrscr( );

while(n>=0)

printf("\n %d", n-- );

getch( );

}

/* To extract the individual digits of the given value */

#include

main()

{


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int n , r; clrscr();

printf(" Enter a value :");

scanf("%d" , &n ) ;

while(n>0)

{

r = n % 10 ;

printf( " \n %d " , r ) ;

n = n / 10;

}

getch();

}

/* To find the reverse value for the given number */

#include

main()

{

int n , r , rev=0 ; clrscr();

printf(" Enter the required value :");

scanf("%d" , &n);

while(n>0)

{

r=n%10;

rev=rev*10+r ;

n=n/10;

}


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printf("\n Reverse Value = %d " , rev );

getch();

}

=> Nested while Statements:

Grouping or using one or more while statements with in an another while statement, is referred

as Nested while statements.

Syntax:

while()

{

Statements;

while()

{

m n => mxn

.................

}

Statements;

}

/* Sample program for nested while statements - output */

#include

main()

{

int x=1 , y ; clrscr();

while( x


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y=1;

while( y Write programs for the following outputs

1. 3 3 2. 1 1

2 3 2 2

1 3 3 3

3 2 1 1

2 2 2 2

1 2 3 3

3 1 1 1

2 1 2 2

1 1 3 3

3. 4.

1 1 2 3 4 5


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1 2 1 2 3 4

1 2 3 1 2 3

1 2 3 4 1 2

1 2 3 4 5 1

..........

1 2 3 4 5 6 7 ....n

3.

/* output3 */

#include

main()

{

int x=1 , y , n ; clrscr();

printf(" Enter value for n:");

scanf("%d" , &n ) ;

while( x


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}

getch( );

}

/* To generate multiplication tables from 1 to 10 */

#include

main()

{

int x=1,y; clrscr();

while(x


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{

int n , r , n1 , s=0 ;

clrscr( );


scanf("%d" , &n ) ;

n1=n;

while( n>0)

{

r = n%10;

s=s + r * r * r ;

n= n / 10;

}

if(s==n1)

printf(" Given number is an Armstrong ");

else

printf(" Given number is not an Armstrong");

getch();

}

/* To generate all Armstrong nos */

#include

main()

{

int n=100 , r , n1 , s ;

clrscr( );


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while(n0)

{

r=n1%10;

s=s+r*r*r;

n1=n1/10;

}

if(s==n)

printf(" \n %d ",n);

n++;

}

getch();

}

/* To find the Hail Stone Value for the given number */

#include

main()

{

int n ,count ; clrscr();

printf(" Enter a number :");

scanf("%d" , &n);

for(count=0 ; n>1 ; count++)


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{

if ( n % 2 == 0 )

n=n / 2;

else

n= n * 3 + 1 ;

}

printf(" Hail Stone Value = %d",count);

getch();

}

2. for Statements:

It is also an iterative control / loop statement that repeats the execution of the

given set of statements for repeated n number of times, until the given condition is met or satisfied.

This statement is same as while statement with only difference in the place of

specifying the initializations, condition and modification, which are specified as parameters with for

statement.

Syntax:

for( Initializations ; ; Modifications )

{

Statement 1;

.....................

Statement n;

}

/* To generate natural numbers from 1 to 20 */

#include


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main()

{

int n; clrscr();

for(n=1 ; n


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scanf("%ld" ,&n );

for(f=1 ; n>=1 ; n--)

f=f*n;

printf(" \n Factorial Value = %ld" , f);

getch( );

}

/* To find whether the given number is prime or not */

#include

main( )

{

int n , f , d ; clrscr();

printf(" Enter the required number :");

scanf("%d" , &n ) ;

for(f=0 , d=1 ; d


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}

=> To find whether the given value is pallindrome number or not

2.

/* To generate an output using nested for statements */

#include

main()

{

int x,y,sp=20,k; clrscr();

for(x=1 ; x


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printf(" %d",y);

printf("\n");

sp+=2;

}

getch();

}

=> Nested for Statements:

Grouping or using one or more for statements within an another for statement is referred as

Nested for statements.

Syntax:

for( Initializations1 ; ; Modifications1 )

{

Statement 1;

for( Initializations2 ; ; Modifications2 )

{

Statement 1;

m n --> mxn

Statement n;

}

Statement n;

}


#include


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main()

{

int x , y ; clrscr();

for( x=1 ; x


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1 *

1 2 * *

1 2 3 * * *

1 2 3 4 * * * *

1 2 3 4 5 * * * * *


#include

main()

{

int x , y , sp=20 , k ; clrscr();

for(x=1 ; x


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1 2 3

1 2 3 4 5

1 2 3 4 5 6 7

1 2 3 4 5 6 7 8 9

/* To generate all prime numbers below the given number */

#include

main( )

{

int x, n , f , d ; clrscr( );

printf(" Enter the maximum prime required number :");

scanf("%d" , &x);

for(n=1 ; n


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1. * * * * * * * * *

* * * * * * *

* * * * *

* * *

*

/* To generate the following output */

#include

main()

{


for(x=9 ; x>=1 ; x-=2)

{

for(k=1 ; k


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1 2 3

1 2 3 4 5

1 2 3 4 5 6 7

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7

1 2 3 4 5

1 2 3

1

3.

1

1 2 1

1 2 3 2 1

1 2 3 4 3 2 1

1 2 3 4 5 4 3 2 1

/* To generate the following output */

#include

main()

{


for(x=1 ; x


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printf(" %d",y);

for(y-=2; y>=1; y--)

printf(" %d",y);

printf("\n");

sp--;

}

getch();

}

=> Wap to generate multiplication tables from the given starting number till the given ending number

3. do while Statement:

It is also a loop / iterative control statement that repeats the execution of the given set of

statements for repeated n number of times until the given condition is met or satisfied.

This statement is similarly to while statement, with only difference in the place of condition

evaluation i.e. in while the condition is evaluated at the beginning of the loop statement where as in do

while the condition is evaluated at the end of the loop statement, so in do while the loop statements

gets executed at least for once.

Syntax:

do

{

Statement 1;

Statement 2;

.....................

Statement n;


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}while() ;

Ex:

int n=0; int n=0;

while(n>=20) do

{ {

printf("\n %d",n); printf("\n %d",n);

n++; n++;

} }while (n>=20);

=> No Output => 0

=> Write a program to generate the following menu

GENERATE MENU

1. EVEN NUMBERS

2. ODD NUMBERS

3. ASCII CODES & CHARS

4. FIBONNACCI SERIES

5. ARMSTRONG NOS

6. PRIME NOS

7. EXIT

ENTER U'R CHOICE:

/* To generate a menu */


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#include

main()

{

int choice,n,n1,r,s;

do

{

clrscr();

gotoxy(35,7); printf(" GENERATE MENU");

gotoxy(30,9); printf(" 1. EVEN NUMBERS");

gotoxy(30,10); printf(" 2. ODD NUMBERS");

gotoxy(30,11); printf(" 3. ASCII CHARS & CODES");

gotoxy(30,12); printf(" 4. FIBONNACCI SERIES");

gotoxy(30,13); printf(" 5. ARMSTRONG NUMBERS");

gotoxy(30,14); printf(" 6. PRIME NUMBERS");

gotoxy(30,15); printf(" 7. EXIT");

gotoxy(30,17); printf(" ENTER UR CHOICE:");

scanf("%d",&choice);

switch(choice)

{

case 1: for(n=2 ; n


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n+=2;

} break;

case 3: for(n=0 ; n


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case 6: for(n=1 ; n


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....................

Statement n;

}

/* Sample program for true statement */

#include

main()

{

int n=0; clrscr();

while(1)

{

printf("\n %d",n);

n++;

if(n>20) break;

}

getch();

}

=> To find sum of the given 10 numbers into an array

#include

main()

{

int n[10] , id , s ; clrscr();

printf(" Enter ten values :");

for( id=0; id


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printf(" Given numbers are ");

for( id=0, s=0 ; id


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[Subscript];

Where

typename => Any primary data type name

Arrayname => Common identity for the array

Subscript => size i.e. no. of elements

Ex:

int n[5];

char name[20];

float p[4];

double d[10];

int a[10], b[5];

When needed we can represent the entire array including all the elements together by a single

common identity known as Arrayname, or if necessary we can also derepresent the individual elements

of an array using Arrayname followed by index numbering, which is automatically assigned by the

Compiler starting from 0 (zero) and ending at Subscript-1.

/* To read and print 5 values into an array */

#include

main()

{

int x[5] , id ; clrscr();

printf(" Enter five values :");

for(id=0 ; id


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for(id=0 ; id for ( id=4 ; id>=0 ; id - - )

printf("\n %d" , x[id] );

getch( );

}

=> To find sum of the given 10 numbers into an array

/* To count total number of even and total number of odd

occured within the given array of 10 values */

#include

main()

{

int x[10] , id , e , d ; clrscr();

printf(" Enter ten values :");

for(id=0 , d=0 , e=0 ; id


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getch();

}

=> To count total number of positive, negative and zero's occured within the given array of 10 numbers

/* To search for the given element within the given array of n numbers */

#include

main()

{

int x[50] , n , i , ele ; clrscr( );

printf(" How many values to be accepted :");

scanf("%d" , &n ) ;

printf(" Enter %d values " , n ) ;

for(i=0 ; i


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if( i==n )

printf(" Given element is not found ");

else

printf(" Given element is found at %d position" , i+1 ) ;

getch();

}

/* To sort the given array of n numbers in ascending order */

#include

main()

{

int x[50] , n , i , j , temp ; clrscr();

printf(" How many values to be accepted :");

scanf("%d" , &n ) ;

printf(" Enter %d values " , n ) ;

for(i=0 ; i


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x[ j ]=temp;

}

printf(" Ascending Order of Given Values are :");

for(i=0 ; i To sort the given n number of elements in an array in descending order

=> To store the first 10 even numbers into an array and print them

/* To store the first 10 even numbers into an array and print them*/

#include

main()

{

int n[10] , i , e ; clrscr();

for(i=0 , e=2 ; i


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2. Double Dimensional Arrays:

These are the matrix type of variables where the memory for the elements is allocated in two

dimensional format i.e. in the form of rows and columns, so while declaring these variables we need to

specify two subscripts (sizes) i.e. row subscript and column subscript

Syntax: Row Column

[Subscript][Subscript];

Ex:

int x[3] [3];

char str[10] [20] ;

float p[3] [4];

int a[3] [2] , b[4] [3] ;

When needed we can represent the entire array including all the elements together by a single

common identity known as Arrayname, or if necessary we can also derepresent the individual elements

of an array using Arrayname followed by row index numbering and column index numbering, which

automatically starts from 0 (zero) and ending at Subscript - 1.

/* to read elements into 3x3 array and print them in martrix format */

#include

main()

{

int x[3][3] , r , c ; clrscr();

printf(" Enter elements into 3x3 matrix\n ");

for(r=0 ; r


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printf(" Given Matrix is \n");

for( r=0 ; r Write programs to generate the following matrices of 4x4 sizes

1. Null Matrix 2. Identity Matrix 3. Upper Triangular Matrix

0 0 0 0 1 0 0 0 0 5 5 5

0 0 0 0 0 1 0 0 0 0 5 5

0 0 0 0 0 0 1 0 0 0 0 5

0 0 0 0 0 0 0 1 0 0 0 0

4.Lower Triangular Matrix 5.

0 0 0 0 1 5 5 5

7 0 0 0 7 1 5 5

7 7 0 0 7 7 1 5

7 7 7 0 7 7 7 1

/* To generate identity matrix of 4x4 size */

#include

main()


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{

int n[4][4] , r , c ; clrscr();

for( r=0 ; r


90/144

scanf("%d" , & n[r][c] ) ;

printf(" Transpose Matrix is \n");

for(r=0 ; r To find the addition matrix for the given two mxn and pxq size matrices

/* To find the product matrix for the given two matrices of

mxn and pxq sizes respectively */

#include

main()

{

int A[10][10],B[10][10],S[10][10];

int r,c,m,n,p,q,k; clrscr();

printf(" Enter the order of first matrix in terms of rows and columns");

scanf("%d%d",&m,&n);

printf(" Enter the order of second matrix in terms of rows and columns");


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scanf("%d%d",&p,&q);

if(n==p)

{

printf(" Enter elements into first %d x %d matrix \n",m,n);

for(r=0; r


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}

}

else

printf(" Invalid matrices orders so product matrix is not possible");

getch();

}

3. Multi-Dimensional Arrays:

These are the array variables where the memory for the elements is allocated in three or more

dimensional formats, so while declaring these variables we need to specify three or more subscripts.

Syntax:

[Subscript1][Subscript2].....;

Ex:

int n[3][2][3];

=> Initialization of Arrays:

Initializing an array is nothing but assigning the required initial values for the elements of an

array while declaring it, within the declaration statement, may be single dimensional or double

dimensional arrays.

-- Single Dimensional Array Initialization --

Syntax:

[Subscript]= { Data1, Data2, ..... , Datan } ;

Ex:

int n[5] = { 10, 46, 7 , 84 , 22 } ;

int x[ ]={ 10 , 20 , 30 , 40 , 50 , 60 } ;

char str [ ] = { 'C' , 'O' , 'M' , 'P' , 'U' , 'T' , 'E' , 'R' } ;


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-- Double Dimensional Array Initialization --

Syntax: Row Column

[Subscript][Subscript] ={ Data1, Data2, .... , Datan } ;

Ex:

int n[3][3]={ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 } ;

or

int n[ ] [ ]={ { 1 , 2 , 3 } ,

{ 4 , 5 , 6 } ,

{ 7 , 8 , 9 } } ;

String Manipulations

A string is group of characters represented as a single notation. As 'C' doesnot provides any

built-in data type by name string, we are adopting Arrays concept and creating a character array for

storing and manipulating strings, may be of single dimensional format or double dimensional format. In

'C', we are using "%s" format specifier to represent a string. The end of the string is represented by Null

character ('\0')

/* To read and print a string */

#include

main( )

{

char name[20]; clrscr();

printf(" Pls enter your name :");

scanf("%s",name);

printf(" Hi %s, Glad 2 C U ", name);

getch( );


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}

=> gets( ): get string

Built-in 'C' string input function that gets or reads a string (collection of characters including

white spaces) as input from the user through keyboard and stores it within the given character array.

Defined in file

Syntax:

gets();

Ex:

char x[20];

gets(x);

=> puts( ): put string

Built-in 'C' string output function that puts or prints the given string expression on the monitor.

Defined in file

Syntax:

puts();

Ex:

1. puts(name);

2. puts(" Hi, Good Evening ");

/* To read and print a string using string functions*/

#include

main( )

{

char name[20]; clrscr();

puts(" Pls enter your name :");

gets(name);


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puts( name);

getch( );

}

=> strlen( ): string length

=> Returns the length i.e. number of characters available in the given string expression. Defined

in file

Syntax:

strlen();

Ex:

1. strlen(name);

2. strlen(" Satyam Computers");

=> 17

/* To find the length of the given name */

#include

#include

main()

{

char name[20];

int len ; clrscr();

puts(" Pls Enter UR Name :");

gets(name);

len = strlen(name);

printf("Hi %s , Length of Your Name is %d " , name , len) ;

getch();

}


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=> strcpy( ): String Copy

Built in 'C' string function that assigns/copies the given source string expression into the given

character array. Defined in file

Syntax:

strcpy ( , ) ;

Ex:

char x[20] , y[20] ;

gets(x);

strcpy( y , x ) ;

2. char result[5] ;

strcpy(result , "pass" ) ;

/* To copy the given string from first array into second array */

#include

#include

main()

{

char x[20] , y[20];

clrscr();

puts(" Pls Enter The Req. String :");

gets(x);

strcpy( y , x ) ;

printf(" Given string is %s " , x ) ;

printf("\n Copied string is %s " , y ) ;

getch();

}


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=> strcmp( ): String Comparision

Built-in 'C' string function that compares the two given string expressions and returns positive

value when first string is greater than second, negative value when second string is greater than first or

zero when both the strings are same. Defined in file

Syntax:

strcmp(,);

Ex:

1.char x[20],y[10]; gets(x); gets(y);

strcmp(x,y);

2. strcmp("ABC","abc");

=> -32

/* To compare the two given strings */

#include

#include

main()

{

char x[20],y[20];

int check; clrscr();

puts(" Pls Enter The First String :");

gets(x);

puts(" Pls Enter The Second String :");

gets(y);

check=strcmp(x,y);


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if(check>0)

printf(" %s string is greater than %s",x,y);

else if(check strcat( ): String Concatenation

Built-in 'C' string function that is used for contenation i.e. joining of the two given strings as a

single string. Defined in file

Syntax:

strcat(,);

Ex:

char x[20];

strcpy(x,"Satyam ");

strcat(x," Computers");

/* To join the two given strins as single */

#include

#include

main()

{

char x[20],y[10]; clrscr();

puts(" Pls Enter The First Part of the String :");


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gets(x);

puts(" Pls Enter The Last Part of the String :");

gets(y);

strcat(x,y);

printf(" Concatenated string is %s",x);

printf("\n Last Part of the String is %s",y);

getch();

}

FUNCTIONS

(Self contained block or program used for a particular sub task)

As 'C' is a modular programming language, function is a block or module of a program consisting

of set of ordered statements related to perform a particular sub task, having a unique identity known as

function name.

Features:

=> Easy readability and understandability

=> Easy Debugging of the errors

=> Provides Modular programming feature

=> Reusability of the code

=> Sharing of the work

=> Reduces the code and saves time and money, etc.

In 'C', functions are classified into three types:

1. Library Functions


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2. Macros / Defined Functions

3. User Defined Functions

1. Library Functions:

These are the pre-defined functions of the 'C' language that are available within the compiler in

the form of library files known as Header files.

Ex:

printf( ), scanf( ), getchar( ), clrscr( ), strlen( ), etc.

2. Macros / Defined Functions:

These are the defined functions consisting of single executable expression, which are to be

defined using "#define" directive, as pre-processor directive statement.

Syntax:

#define ([])

Ex:

#define Sum(a,b) (a+b)

#define Area(r) (3.14159*r*r)

#define Big(x,y) (x>y)?x:y

/* To find area of a circle by defining a Macro */

#include

#define Area(x) (3.14159*x*x)

main( )

{

int r; clrscr();



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scanf("%d" , &r);

printf(" Area of Circle = %f", Area(r));

getch();

}

/* To find biggest and smallest among two given numbers by defining Macros using Ternary Operators

*/

#include

#define Max(a,b) (a>b)?a:b

#define Min(a,b) (a Write a program to find biggest and smallest among three given numbers by defining macros using

ternary operators

3. User-Defined Functions:

These are the functions that are defined by the user for his own need or requirement, in the

form of separate module / block by grouping the necessary set of statements related to perform a

particualr sub task.


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Each function is assigned with a unique identity known as functionname. Functions may or may

not takes parameters and similarly they may or may not returns value / data.

To manipulate user defined functions in 'C', follow the following three steps:

1. Function Declaration (Prototype Statements)

2. Function Definition

3. Function Call / Invoke

1. Function Declaration:

The first step to manipulate user defined functions is to declare the functions, to give the

necessary specification to 'C' compiler about the functionname, number and type of parameters and

type of return value.

The statements used for declaration of functions are known as function prototype statements.

Syntax: Formal

[] ( [] );

Where

rt-type => return data type name (default it takes "int" type)

Functionname => Function identity

Parameters list => The type of data items passed from the calling point

Ex:

1. int Sum(int,int);

OR

Sum(int , int);

2. float Area( int );

3. int Big(int , int , int);

4. int Reverse( int );


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2. Function Definition:

The second step after function prototype statements is to define the functions, which is nothing

but associating the necessary code(statements) to the functions in the form of separate blocks/modules,

may be before the main() or after the main() block.

Function definition consists of two parts:

1. Function Header Row

2. Function Body

Syntax: Formal

[] ( [] ) -> Fn Header Row

{

Statement 1;

.................... -> Fn Body

Statement n;

}

Ex:

int Sum(int x,int y)

{

return(x+y);

} OR

Sum(x , y)

int x , y;

{

return(x+y);

}


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3. Function Call / Invoke :

The last step in manipulation of user defined functions is to call or invoke the functions defined

within the main() block and pass the necessary data in the form of parameters, for their execution.

Syntax: Actual

( [] );

Ex:

c=Sum(10,20); OR printf(" Sum = %d ", Sum(a,b));

=> Parameters :

These are the arguments that represents the data, to be transferred between two blocks of a

program. In 'C', parameters are classified into two types:

1. Actual Parameters

2. Formal Parameters

Actual Parameters are the arguments that are used for passing the necessary data to the

function called from its calling point, which may a constant, an operand, an operator, a formula, a sub

function call.

Formal Parameters are the arguments that are used for receiving the data passed from the

calling point, which are used within the function header row (fn definition). As the formal parameters

are used for the first time within the function, they needed to be declared there and then. The number

and type of formal parameters should be equal and same as that of actual parameters passed from the

calling point.

/* To find the area of a circle by defining a UDF */

#include

float Area(int); /* Fn Prototype Statement */

main( )


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{

int r;

clrscr();


scanf("%d",&r);

printf(" Area of a Circle = %f" , Area(r) ); /* Fn Call */

getch();

}

float Area(int x) /* Fn Definition */

{

return ( 3.14159 * x * x );

}

/* To find biggest and smallest among two given nos by defining UDFs */

#include

main()

{

int m,n; clrscr();


scanf("%d%d",&m,&n);

printf(" Biggest = %d ", Big(m,n) );

printf("\n Smallest = %d ", Small(m,n) );

getch();

}


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Big(int x,int y)

{

if(x>y)

return(x);

else

return(y);

}

Small(int m,int n)

{

if(m To find the area and perimeter of a rectangle by defining UDFs

=> To find the smallest among three given numbers by defining UDF

Type of User Defined Functions:

Depending on the parameters and return value of the functions, they are divided into four

types:

1. Functions with parameters and with return value.

2. Functions with parameters and no return value.

3. Functions with no parameters but returns value.


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4. Functions with no parameters and no return value.

/* To swap the two given numbers by defining a UDF */

/* Fn with parameters but no return value */

#include

swap(int x,int y)

{

int z;

z=x;

x=y;

y=z;

printf("\n After swapping values are %d and %d ",x,y);

}

main()

{

int a,b; clrscr( );

printf(" Enter two values :");

scanf("%d%d" , &a, &b);

printf(" Before swapping values are %d and %d ",a,b);

swap(a,b);

getch();

}


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/* To find the factorial value for the given number by defining UDF */

#include

int fact(int x)

{

int f;

for(f=1;x>=1; x--)

f=f*x;

return(f);

}

main()

{

int n; clrscr();

printf(" Enter the required number :");

scanf("%d" , &n);

printf(" Factorial Value = %d ", fact(n) );

getch();

}

/* To generate fibonnacci series below n by defining UDF */

#include

fibo(int n)

{


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int a,b;

for(a=0 , b=1 ; b=65 && x=97 && x


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int is_digit(char x)

{

if(x>=48 && x


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if(is_digit(m))


else

if(is_space(m))

printf(" Given character is a blank space ");

else

printf(" Given character is a special character ");

getch();

}

=> Passing of Arrays as Parameters to Functions:

In 'C', when we are in need to pass group of same type of data items as parameters to a single

function, rather than passing them individually one by one, we can pass them together as a single

parameter in the form of an array, which may be single or double dimensional format.

To pass Single dimensional array as parameter to a function, use only the arrayname as actual

parameter at the function calling point and declare same type of dummy array without subscript as

formal parameter within the function header row. Here the dummy array is not a copy of the actual

array, instead it is the reference for the actual array i.e. directly the original elements are manipulated

by the dummy array (Call by Reference).

/* To read and print 5 values into an array by defining UDFs */

#include

read_array(int x[])

{

int i;

for(i=0 ; i


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}

main()

{

int n[5]; clrscr();

printf(" Enter 5 values :\n");

read_array(n);

printf(" Given values are ");

display_array(n);

getch();

}

display_array(int x[])

{

int i;

for(i=0 ; i Program to read 10 numbers into an array and find their sum by defining UDFs

/* To find biggest among n given numbers into an array by defining UDFs */

#include

read_array(int m[ ],int n)

{


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int i;

for(i=0 ; i


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return(big);

}

/* To sort the n given numbers into an array in ascending order

by defining UDFs */

#include

read_array(int m[],int n)

{

int i;

for(i=0 ; i


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display_array(x,n);

getch();

}

sort_array(int m[],int n)

{

int i,j,temp;

for(i=0 ; i


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When we are in need to pass double dimensional array as parameter to a function, use only the

array name as actual parameter at the function calling point and same type of double dimensional

dummy array as formal parameter without specifying the row subscript but giving the column subscript.

(Call by reference)

/* To read and print elements into 3x4 matrix by defining UDFs */

#include

read_matrix(int m[][4])

{

int r,c;

for(r=0 ; r


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display_matrix(int m[][4])

{

int r,c;

for(r=0 ; r


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main( )

{

int a , b; clrscr( );


scanf("%d%d" , &a , &b);

printf(" Sum = %d ", Sum(a,b) );

getch( );

}

int Sum(int x, int y)

{

return(x+y);

}

--> Where

a & b => Local to main ( )

x & y => Local to Sum ( )

2. Global Variables:

These are the variables that are globalized i.e. their accessing is limited to the entire program

that is in all the blocks / modules and gets released (dead) as soon as the program's execution is ended.

These variables needed to be declared outside the blocks at the beginning of the program as Global

Declaration statements.

/* Sample program for global variables */

#include

int a , b;


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main( )

{

clrscr( );


scanf(" %d%d ", &a , &b);

printf(" Smallest = %d ", Small( ) );

getch( );

}

int Small( )

{

if(a Where

a & b => Global Variables for the entire program

3. Static Variables:

These are the variables whose memory remains unchangable through out the program

execution for all the other remaining declaration of the variables with the same name.

To declare static variables, preceed the variables declaration with "static" keyword.


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Syntax:

static ;

ex:

static float p;

static int a,b;

/* Sample program for static variables */

#include

main()

{

static int a,b;

clrscr();


scanf("%d%d",&a,&b);

printf(" Product of a and b = %d",product(a,b));

getch();

}

int product(int a, int b)

{

return(a*b);

}

---> Where

a & b => static variables


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/* Sample program for static variables */

#include

main()

{

static int x=50;

clrscr();

printf("\n x = %d",x);

sample();

getch();

}

sample( )

{

int x;

x=x+5;

printf("\n %d ", x);

}

=> Recursions:

It is the concept of calling a function within it self for repeated n number of times, to reduce the

code and to increase the execution speed of the program. In recursive function, we need to specify a

condition to stop the recursive execution otherwise the program execution will enter into infinity loop.

/* To find the factorial value for the given number */

/* By using Non-recursive concept */


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scanf("%d", &n);

printf( " Factorial Value = %d",fact(n));

getch();

}

int fact(int x)

{

if(x==1)

return(1);

else

return(x * fact(x-1));

}

/* To swap the two given numbers by using global variables */

/* Functions with no parameters and no return value */

#include

int x , y;

swap( )

{

int temp;

temp=x;

x=y;


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y=temp;

}

main()

{

clrscr();


scanf("%d%d",&x,&y);

printf(" Before swapping x = %d and y = %d" , x , y );

swap( );

printf("\n After swapping x = %d and y = %d " , x , y );

getch( );

}

POINTERS

These are of non-primitive derived data type concept.

Pointers are special variables that holds the address of the data stored, rather than directly

holding the data (Unlike the ordinary variables). Pointers are mainly used for the following features:

1. It increases the program execution speed, as it is directly pointing the address

2. It is provides memory resident programming feature, using which we can directly manipulate

or use the system's internal memory.

3. It is also used for managing dynamic type of memory, which is allocated at the time of

execution of the program and which is non-static in size.

4. It is also used for increasing the size of an array at the time of program execution.

5. It saves the time and also saves the memory

6. It is also used for creation of new variables at run time, etc.


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Follow the following format for declaration of pointer variables:

Syntax

*;

Where

typename => any primitive data type name

* (Asterisk) => Pointer operator / Value at Address operator / Indirect operator

Ex:

int *p;

float *f,*d;

char *st;

/* Sample program for pointers */

#include

main()

{

int n,*ptr; clrscr();

ptr=&n;


scanf("%d",ptr);

printf("\n Value at n = %d",n);

printf("\n Address of n = %ld",&n);

printf("\n Value at ptr = %ld",ptr);

printf("\n Value at Address = %d", *(&n));

printf("\n Value at pointer = %d",*ptr);

getch();


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}

/* To read and print a character using pointer */

#include

main()

{

char ch,*p; clrscr();

p=&ch;

printf(" Enter a character :");

*p=getchar();

printf(" Given character = %c",*p);

getch();

}

/* To read and print 5 values into an array using pointers */

#include

main()

{

int n[5],*p,i; clrscr();

p=n; /* p=&n[0]; */

printf(" Enter 5 values :");

for(i=1 ; i


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}

printf(" Given values are :");

for(p=n , i=1 ; i for(n-- , i=1 ; i To find sum of the given 10 numbers into an array using pointers

/* To find biggest among the given 10 numbers into an array using pointers */

#include

main()

{

int n[10],*p,i,big; clrscr();

p=n; /* p=&n[0]; */

printf(" Enter 10 values :");

for(i=1 ; i


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printf(" \n Biggest = %d",big);

getch();

}

=> Function Calls:

In 'C', the user defined functions can be called or invoked in two different methods, they are:

1. Call by Value (Pass by Value)

2. Call by Reference (Pass by Reference)

In Call by Value method, we create dummy variables as formal parameters within the function

header row and receive the copy of the actual parameters passed from the calling point, manipulating

which within the function does not affects the original actual parameters data/value.


/* Using Call by Value method */

#include

swap(int x,int y)

{

int z;

z=x;

x=y;

y=z;

printf("\n After swapping values are %d and %d ",x,y);

}


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main()

{

int a,b; clrscr( );


scanf("%d%d" , &a, &b);

printf(" Before swapping values are %d and %d ",a,b);

swap(a,b);

getch();

}

In Call by Reference method, we create pointer type of variables as formal parameters within

the function header row and receives the reference (address) of the actual parameters from the calling

point, manipulating which within the function directly affects the original actual parameters data/value.


/* Using Call by Reference method */

#include

swap(int *x, int *y)

{

int z;

z=*x;

*x=*y;

*y=z;


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}

main()

{

int a,b; clrscr( );


scanf("%d%d" , &a, &b);

printf(" Before swapping values are a = %d and b = %d ",a,b);

swap(&a,&b);

printf("\n After swapping values are a = %d and b = %d ", a, b);

getch();

}

STRUCTURES

These are of non-primitive user defined data type concept, which is encapsulating (grouping)

collection of different type of data items together for storing related information, which can be referred

by a single common identity known as Structure name or Tag name.

In general, a structure can also be defined as "Collection of different type of data items grouped

together for storing related information". The different data items grouped in a structure can be

referred as members.

To manipulate structure in 'C', we have to follow the following three steps:

1. Structure Definition

2. Declaration of Structure Variables

3. Accessing the individual members


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1. Defining a Structure:

As structures are of user-defined data type concept, first we have to define the structure to give

necessary specifications to the 'C' compiler, about the structure name and scopes of the members

(member names and their types).

Syntax:

struct

{

;

;

.........................

;

};

Ex:

struct Sample

{

int x;

char y;

float z;

}; (Allocates 7 Bytes for Sample Structure Variable)

The members of a structure can not only be of primitive data type, instead if required they can

also be of non-primitive user defined data type, may be of pointers, arrays, sub-structures.

Ex: 1.

struct Student

{


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int rno,s1,s2,s3,total;

char name[20],result[5];

float avg;

}; (Allocates 39 bytes for student structure variable)

2.

struct Emp

{

int eno;

char *name;

float basic;

};

3.

struct date

{

int dd,mm,yy;

};

struct Stu

{

int rno;

char name[20];

struct date dob; --> Nesting of structures

};

2. Declaration of Structure Variables:


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After defining a structure, we have to declare the variabels pertaining to the structure defined,

for storing the data. The variables of a particular structure type are referred as structure variables

(Objects).

Syntax:

struct ;

Ex:

struct Sample s;

struct Student x;

struct Emp e1,e2,e3;

struct Stu x,y;

When we are in need of three or more variables of same structure type, rather than declaring

them individually one by one, we can declare them as array type may be of single or double dimensional

format.

Syntax:

struct [Subscript]...;

Ex:

struct Student a[5];

struct Emp e[3][2];

3. Accessing the Individual Members of a Structure Variable:

The last step in manipulation of structure is to access the individual members of a structure

variable, by using structure variable name followed by member accessing operator ( . ) and member

name.

Syntax:

.

Ex:

s.x x.rno e1.eno


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s.y x.name e1.name

s.z x.s1 ..... x.result .......x.avg e1.basic

x.rno x.name x.dob.dd x.dob.yy x.dob.mm

a[i].rno a[i].name ..... a[i].avg

e[r][c].eno e[r][c].name e[r][c].basic

/* To read and print a single student record using structures */

#inc

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c Language by SRIDHAR