In C++ the braces of and if or an else clause can contain another if statement. There are known as nested if statements.

In simple terms a nested if is when you write an IF inside another IF braces.

This is the basic structure of a nested if.

if( boolean_expression 1)
{
   // Executes when the boolean expression 1 is true
   if(boolean_expression 2)
   {
      // Executes when the boolean expression 2 is true
   }
}

 

And of course we can nest else if in the similar way as you nest the if statement.

This is an example of a program with nested if-else.

#include <iostream>
using namespace std;
 
int main ()
{
   int marks = 55;
   if( marks >= 80) {
      cout << "U are 1st class !!";
   } 
   else {
      if( marks >= 60) {
          cout << "U are 2nd class !!";
      }  
      else {
	if( marks >= 40) {
  	  cout << "U are 3rd class !!";
	}
	else {  
	  cout << "U are fail !!";
        }		  
      }
   }
   return 0;
}

 

And this will be the output:

U are 3rd class !!

 

-The Admin.