9. If else-if ladder and Nested if Statements

 

If else-if ladder Statement

The if else-if ladder statement is an extension of the if-else statement. It is used in the scenario where there are multiple cases to be performed for different conditions. In if else-if ladder statement, if a condition is true then the statements defined in the if block will be executed, otherwise if some other condition is true then the statements defined in the else-if block will be executed, at the last if none of the condition is true then the statements defined in the else block will be executed. There are multiple else-if blocks possible.

#include <stdio.h>

int main()
{
   int number;
   printf("Enter a number : ");
   scanf("%d", &number);
   if (number == 10){
      printf("Number is equals to 10.");
   }
   else if (number == 50){
      printf("Number is equals to 50.");
   }
   else if (number == 100){
      printf("Number is equals to 100.");
   }
   else{
      printf("Number is not equal to 10, 50 or 100.");
   }
   return 0;
}

Output :

Enter a number : 50
Number is equals to 50.
Enter a number : 75
Number is not equal to 10, 50 or 100.

Program to calculate the grade of the student according to the specified marks

#include <stdio.h>

int main()
{
   int marks;
   printf("Enter your marks : ");
   scanf("%d", &marks);
   if (marks > 85 && marks <= 100){
      printf("Congrats!! You scored grade A .....");
   }
   else if (marks > 60 && marks <= 85){
      printf("You scored grade B+ .....");
   }
   else if (marks > 40 && marks <= 60){
      printf("You scored grade B .....");
   }
   else if (marks > 30 && marks <= 40){
      printf("You scored grade C .....");
   }
   else {
      printf("Sorry, You are fail .....");
   }
   return 0;
}

Output :

Enter your marks : 10
Sorry, You are fail .....
Enter your marks : 95
Congrats!! You scored grade A .....
Enter your marks : 40
You scored grade C .....

Nested-if in C

A nested if in C is an if statement that is the target of another if statement. Nested if statements means an if statement inside another if statement.

#include <stdio.h>

int main()
{
   int x, y;
   printf("Enter two numbers : ");
   scanf("%d %d", &x, &y);
   if (x != y){
      if (x>y){
         printf("%d is greater.", x);
      }
      else{
         printf("%d is greater.", y);
      }
   }
   else{
      printf("Both numbers are equal.");
   }
   return 0;
}

Output :

Enter two numbers : 8 2
8 is greater.
Enter two numbers : 2 8
8 is greater.
Enter two numbers : 8 8
Both numbers are equal.