Conditional Statements

These are statements within our program which are conditionally executed.
To conditionally execute statements C Language provides us different control structures and operators.

if statement
switch statement
Ternary/conditional operator

If statement

It is used to conditionally execute a block of statements.

If condition is true then statements within if block are executed and then program control is transferred to next statements.
If condition is false then statements within else block are executed and then program control is transferred to next statements.

Syntax:

if(condition)
  {
    statements
    ----------
  }
else
  {
    statements
    ----------
  }	
next statements

Note: else block is optional

Boolean expressions

Condition can be specified by using a Boolean expression .i.e. an expression whose result is true or false.

true – 1
false - 0

Boolean expression can be created by using relational and logical operators.

Relational Operators: < > <= >= == !=
Logical Operators: && || ! and or not

#Write a program to read a no and check if it is an even no or odd no.

  #include⁢stdio.h>
  main()
  {
    int a;
    printf("Enter a Number ");
    scanf("%d",&a);
    if( a%2==0 )
        printf("Number is EVEN");
    else
        printf("Number is Odd");
  }

Enter a Number 26 
Number is Even

#Write a program to read 3 angles and check if triangle can be formed or not.

  #include⁢stdio.h>
  main()
  {
    int a,b,c;
    printf("Enter 3 Angles ");
    scanf("%d %d %d",&a,&b,&c);
    if( a+b+c == 180 )
        printf("Triangle can be formed");
    else
        printf("Triangle cannot be formed");
  }

Enter 3 Angles 60 60 60
Tirangle Can be formed

#Write a program to read a no and check if it is a 2 digit no or not.

  #include⁢stdio.h>
  main()
  {
    int a;
    printf("Enter a Number ");
    scanf("%d",&a);
    if( a >= 10 && a <= 99 )
        printf("It is a 2 digit number");
    else
        printf("It is not a 2 digit number");
  }

Enter a Number 26
It is a 2 digit Number

#Write a program to read a no and check if it is a 4 digit no or not. If it is a 4 digit no then find sum of its digits.

  #include⁢stdio.h>
  main()
  {
    int a;
    int x,y,z,w,s;
    printf("Enter a Number ");
    scanf("%d",&a);
    if(a>=1000 && a<=9999)
    {
        printf("It is a 4 digit number");
        w=a % 10;
        x=a / 10 % 10;
        y=a / 100 % 10;
        z=a / 1000;
        s=w + x + y + z;
        printf("sum of digits is %d",s);
    }
    else
        printf("It is not a 4 digit number");
  }

Enter a Number 2656 
It is a 4-digit number
sum of number is 19

#Write a program to read marks for 5 subjects and check if student is pass or fail. Passing marks 40 per subject.

  #include⁢stdio.h>
  main()
  {
    int a,b,c,d,e;
    printf("Enter Marks for 5 subjects ");
    scanf("%d %d %d %d %d",&a,&b,&c,&d,&e);
    if(a>=40 && b>=40 && c>=40 && d>=40 && e>=40 )
        printf("Student is Passed");
    else
        printf("Student is Failed");
  }

Enter marks of 5 subject 65 85 62 72 39 
Student is Passed

CCITcoder

Introduction to C

DataType and Operation

Conditional statements

Iterative statements

Functions

Array

Pointers

Structures

File I/O

Graphics

Additional Features