C if-else Statements

Flow Control

C if-else Statements

If else statements in C is also used to control the program flow based on some condition, only the difference is: it’s used to execute some statement code block if expression is evaluated to true, otherwise executes else statement code block.

The basic format of if else statement is:

Syntax:

if(test_expression)
{
   //execute your code
}
else
{
   //execute your code
}

Figure – Flowchart of if else Statement:

Example of a C Program to Demonstrate if else Statement

 Example:

#include<stdio.h>

main()
{
  int a, b;

  printf("Please enter the value for a:");
  scanf("%d", & amp; a);

  printf("\nPlease the value for b:");
  scanf("%d", & amp; b);

  if (a & gt; b) {  
    printf("\n a is greater");
  } else {  
    printf("\n b is greater");
  }
}

Program Output:

Example:

#include<stdio.h>

main()
{
  int num;
  printf( & quot; Enter the number: & quot;);
  scanf( & quot; % d & quot;, & amp; num);

  /* check whether the number is negative number */
  if(num < 0)
  printf("The number is negative."); 
  else
  printf("The number is positive.");    
} 

Program Output: