C PROGRAMMING BASICS- COMPUTER PROGRAMMING UNIT II

UNIT-II

C PROGRAMMING BASICS

PREPARED BY K,NITHIYA AP/IT

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CHARACTER SETC CHARACTER SET

Execution Character Set

Source Character Set

Digits

Alphabets

Special

Character

White Space Character

SpaceEscape

Sequence


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A Character denotes an alphabet, digit or a special character.

Lowercase Letters – A,B,C….. Z

Uppercase Letters - a,b,c…… z

Digits – 0,1,2,3,…7,8,9

+ Plus Sign - Minus Sign , Comma

* Asterisk / Slash = Equal to

@ At Symbol < Less Than : Colon

; Semicolon PREPARED BY K,NITHIYA

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It will work at the execution time only and it cannot be printed.It always represented by a backslash(\) followed by a character.


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The smallest individual units of a c program are known as tokens

It can be categorized into following ways

C tokens

operatorsSpecial symbolstringconstantsIdentifier

sKeywords


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Keyword is a reserved keyword that has a particular meaning It should be in lower case There are 32 keywords in c language

S.NO

keyword S.NO

keyword S.NO keyword S.NO

keyword keyword

1 auto 8 do 15 goto 22 signed 29.unsigned

2 break 9 double 16 if 23 sizeof 30.void3 case 1

0else 17 int 24 static 31.volatile

4 char 11

enum 18 long 25 struct 32.while

5 const 12

extern 19 register

26 switch

6 continue

13

float 20 return 27 typedef

7 default 14

for 21 short 28 unionPREPARED BY K,NITHIYA


It can be a variable name and function name etc. Maximum length of an identifier is 31 Special character are not allowed except(_).

Valid invalidnithiya Nithya#NITHIYA Nith ya ->blank spaceNithya3 AutoNithya 3nithya


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10-356

4600.5-0.963 ‘A’

‘*’“A”

“CSC”


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Variables are named locations in memory that are used to hold a value that may be modified by the program.

K5.ico ANIMATAY006.ICO

The syntax for declaring a variable is

Data type Variablename;

Valid Examples :CSC avg_val

m1 Chennai Anumark_1


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RULES for framing a variable :

The first character in the Variable name must be an alphabet

Alphabets can be followed by a number of digits or

underscores

No commas or Blank spaces are allowed within a variable

name

No Special character other than Underscore(_) can be used in

a variable name.

The variable name should not be a keyword

Variable names are case sensitive

It should not be of length more than 31 charactersPREPARED BY K,NITHIYA


INTIALIZING VARIABLEAssigning some value to the variable is known as intializationSYNTAX:Data type variable name=value;ExampleInt a=10;

SCOPE OF VARIABLE1.Local variable 2.Global variable


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Scope of variable

definition example

Local variable

Declared inside the block

main(){Int a=8; // local variable}

Global variable

Declared before the main function

Int a=8;Main(){//no of statement}


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C data types

Empty data type

User defined data type

Derived or secondary data type

Primary data type


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PRIMARY DATA TYPES

int float chardouble

1.PRIMARY DATA TYPES

S.NO

Data Type

Explanation Size(bytes) CONTROL STRING

RANGE SYNTAX EXAMPLE

1 int It store numeric values without decimal pointExample:9,10,23

2 bytes %d or %i -32,768 to +32,767

int Variable_name;

int roll_no;

2 float It store the numeric values with decimal pointExample:3.12,47.098

4 bytes %f or %g 3.4E-38 to 3.4E+38

Float Variable_name;

float a;

3 double It store the big number of decimal pointExample:2.13455

8 bytes %if 1.7E-308 to 1.7E+308

Double Variable name;

double b;

4 char It store the single characterExample:’a’,’9’

1 bytes %c -128 to +127 Char Variable name;

char a=“nithiya”;


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1.Array An array is a collection of variable of same data typeSYNTAX: Datatype array_name[array size];Example: int a[10];2.Structures it stores the multiple values of same or different data type

under a single nameSyntax:Struct <struct name>{Member 1;member 2;};

DERIVED DATA TYPE

array pointersunionsstructure

s

EXAMPLE:Struct Student{Char name[10];Int roll_no;};3.UNION A union is store the multiple values of same or different data typeSYNTAX: union <union name>{Member 1; member 2;}EXAMPLE:Union student{Char name[25];}; PREPARED BY K,NITHIYA


4.POINTERS A pointer is holds the memory address of another variableSYNTAX:Data type *variable nameEXAMPLE : int *a

EMPTY DATA TYPEi)Void its represents an empty value


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1.Type Definition

Example: Typedef int age;

age male,female

2.Enumerated Datatype

Example :

enum mon{jan,feb,mar,apr,may,jun,jul,aug,sep,oct,nov,dec };


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USER DEFINED DATA TYPE

Control statement

conditionalunconditiona

l

selective looping

Nested if else

Simple if

If else

If-else if ladder

Switch case

whiledo while

for

gotobreak

continue


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A program is a sequence of one or more instructions The condition will check whether the particular

condition are true (or) not. 1.SIMPLE IF STATEMENT If the condition is true the set of statements are

executed SYNTAX

if(condition){Statement 1;}


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To find the given no is even or odd#include<stdio.h>#include<conio.h>main(){int no;clrscr();printf(“\n Enter the number”);scanf(“%d”,&no);if(no%2==0){printf(The given no is even”);}}

OutputEnter the number24The given no is even


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2.if else statementIt is a two way decision making statementSYNTAX:if(condition){Statement 1;}else{ false statement;}

#include<stdio.h>#include<conio.h>main(){int no;clrscr();printf(“\n Enter the number”);scanf(“%d”,&no);if(no%2==0){printf(The given no is even”);}else{Printf(“The given no is odd”);}

OutputEnter the number

25The given no is odd


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The number of logical conditions is checked for executing various statements SYNTAX if(condition 1) { True statement 1; } else { if(condition 2) { True statement 2; } else { False statement }}

#include<stdio.h>#include<conio.h>Main(){int a,b,c;clrscr();printf(“Enter a,b,c”);scanf(“%d%d%d”,&a,&b,&c);if((a>b)&&(a>c)){printf(“A is greater”);}else{If(b>c){printf(“B is greater”);}else{printf(“C is greater”);}}}

OutputEnter the values of a,b,c4 23A is greater

Nested if-else can be chained with one another

Syntax:if(condition 1)

{

Statement 1;

}

else if(condition 2);

{

Statement 2;

}

else if(condition 3)

{

statement;

}

else

{

Final statement

}

#include<stdio.h>#include<conio.h>Main(){int a,b,c;clrscr();printf(“Enter a,b,c”);scanf(“%d%d%d”,&a,&b,&c);if(a>b){If(a>c){printf(“A is greater”);}else{printf(“C is greater”);} }else if(b>c){printf(“B is greater”);}else{printf(“C is greater”);}}

OutputEnter the values of a,b,c4 23A is greater


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If the value matches with case constant, this particular case statement is executed. if not default is executed.

SYNTAX: Switch (variable) { Case constant 1: statement 1; Break; Case constant 2: Statement 2; Break; .. .. default: Default statement; }

#include<stdio.h>#include<conio.h>Main(){int a=10,b=5;char symbol; clrscr();printf(“Enter the symbol”);scanf(“%c”,&symbol);switch(symbol){case’+’: result=a+b; break;case’-’: result=a-b; break;case’*’: Result=a*b; Break;Case’/’: Result=a/b; break;case’%’: Result=a%b; break;}Default:Printf(“invalid symbol”);}Printf(“the result is %d”,result);}

OutputEnter the symbol:+The result is 15Enter the symbol:%The result is 0


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C PROGRAMMING BASICS- COMPUTER PROGRAMMING UNIT II

Engineering

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