Nested If Statement in Java

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:

import java.util.Scanner;
class Test
{
 public static void main(String []arg)
 {
  Scanner sc;
  sc = new Scanner(System.in);
  int x ;
  System.out.print("Enter any number: ");
  x = sc.nextInt();
 if(x>0) {
  if(x%2 == 0)
   System.out.print("X is EVEN");
  else
   System.out.print("X is ODD");
 }
 else {
   System.out.print("Not Natural Number");
  }
 }//main closed
}//class closed

Enter any number: 12
X is EVEN

Next topic is switch-case statement in Java