Nested if in C++

It is perfectly all right if we write an entire if-else construct within either the body of the if statement or the body of an else statement.

Syntax :

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

Example:

#include<iostream>
using namespace std; 
int main( )
{
 int x ;
 cout<< "Enter any number: ";
 cin>>x;
 if(x>0) {
  if(x%2 == 0)
   cout<< "X is EVEN\n";
  else
   cout<< "X is ODD\n";
 }
 else {
   cout<< "Not Natural Number\n";
 }
 return 0;
}

Enter any number: 12
X is EVEN

Next topic is Switch-Case in C++