Nested If-else

  • In some situation ,nested if -else statement will occur and that would be good for that situation.
  • This statement are nothing but same if-else statement with an another if-else statement in their body.
  • This helps you to perform multiple actions in a single instruction.
  • What makes nested statement to come in action?
    Because, there are some problem which has to be solve by them, and for that situation nested statements becomes efficient.
  • Lets first see its syntax and then we will solve One problem regarding to nested statements.

Syntax

if(condition)
{
//body if block
}
else
{
     if(condition)
      {
            //block of if
      }
     else{     //else block with another else statement.
             if(condition){

                               // if block.
                         }
                         else{

                         // default statement.
                        //if no  condition  matches than this block will get executed
                         
                               }

            }
}

Lets solve a problem , of grades of student.

Q:take an percentage of student as an input and tell them what is their grade.
below displayed table has percentage and grade corresponding to their marks

Percentage and Grades.
Percentage Grade
above 90
O
80 to 90
A
70 to 80
B
60 to 70
C
50 to 60
D
40 to 50
E
below 40
Fail

Solution:

#include<stdio.h>
 void main()
 {
 int per;
 printf("Enter your percentage:");
 scanf("%d",&per);
 if(per > 90){
    printf("Your grade is O");
 }
 else{
    if(per > 80 && per <= 90){
        printf("Your grade is A");
      }
    else{
        if(per > 70 && per <= 80)
           {
            printf("Your grade is B");
           }
         else{
                if(per > 60 && per <= 70)
                  {
                    printf("Your grade is C");
                   }
                else{
                    if(per > 50 && per <= 60)
                        {
                        printf("Your grade is D");
                     }


                    else{
                    if(per > 40 && per <= 50)
                     {
                        printf("Your grade is E");
                     } 
                    else
                        printf("Fail");

                    }
                }
         }
    }
 }
 }

Output: For all types of percentage

Enter your percentage:95
Your grade is O.
Enter your percentage:85
Your grade is A.
Enter your percentage:75
Your grade is B.
Enter your percentage:65
Your grade is C.
Enter your percentage:55
Your grade is D.
Enter your percentage:45
Your grade is E.
Enter your percentage:31
Fail.
  • Above code is just looking lengthy but, when  you will read the code, you  will find it easy.
  • Explanation:
  • For: percentage = 65
  • when condition was checked at first if block it was evaluated false.
  • As you know control goes to else block, so  it went to else block and in that else block there is an if block.
  • Condition was checked in that if block and it also evaluated to false, and  again control went to next else block
  • In that else block there was an another if block, as  condition was checked for
    that if block, but again it evaluated to false, and control went to next else block.
  • That else block also contain an if block, as  condition was checked for that if block but ,This time condition was evaluated to true and it printed that 'Your grade is C'
  • Try to trace grade for other percentage by your own, doing  this you will understand the nested statement better.
  • Try to do more programs on nested statement to understand it better.

Note: If  you have code of one line in your if block you can write it without using the curly braces, In Above code we have used the braces just because you should not get confuse.





                    Practice Programs

  • Programs Regarding If-else Statements
  • Program Regarding Nested If - statements
  • Programs Regarding loops


              Further Topics