The decision control structure

• In decision control statements (C if else and nested if), group of statements are executed when condition is true.  If condition is false, then else part statements are executed.

There are 3 types of decision making control statements in C language. They are,

1. If statement
2. If-else statement
3. Nested if statement

 NOTE- PLEASE FIND THE ATTACHMENT WITH THIS NOTES FOR SYNTAX AND DESCRIPTION OF DECISION CONTROL STATEMENT

 Example program for if statement in C:

      

In “if” control statement, respective block of code is executed when condition is true.

#include<stdio.h>
#include<conio.h>
void main()
{
  int m=40,n=40;
  if (m == n)
  {
      printf("m and n are equal");
  }
getch();
 }

Output:

m and n are equal

Example program for if else statement in C:

      

In C if else control statement, group of statements are executed when condition is true.  If condition is false, then else part statements are executed.

#include <stdio.h>
#include<conio.h>
void main()
{
  int m=40,n=20;
  if (m == n) {
      printf("m and n are equal");
  }
  else {
        printf("m and n are not equal");
  }
 getch();
 }                                               

Output:

m and n are not equal

Example program for nested if statement in C: 

•  In “nested if” control statement, if condition 1 is false, then condition 2 is checked and statements are executed if it is true. 
• If condition 2 also gets failure, then else part is executed.

#include <stdio.h>
#include<conio.h>
void main()
{
int m=40,n=20;
if (m>n)
{
printf("m is greater than n");
}
else if(m<n>
{ 
printf("m is less than n");
}
else
{ 
printf("m is equal to n");
}
getch();
}

Output:

m is greater than n