How to swap two numbers using only two variables in Java

 Here's a program to swap two numbers using only two variables with explanation using Java Programming language.

 import java.io.*;
 
     class swap{
        public static void main(String[]args) throws IOException{
           int a,b;
           DataInputStream din=new DataInputStream(System.in);

           System.out.println("Enter the 1st no.(a): ");
           a=Integer.parseInt(din.readLine());

           System.out.println("Enter the 2nd no.(b): ");
           b=Integer.parseInt(din.readLine());

           a=a+b;
           b=a-b;
           a=a-b;

           System.out.println("The swaping no. is " +a+ "," +b+".");
        }
     }

Output of Program:
 Enter the 1st no.(a): 5
 Enter the 2nd no.(b): 4

 The swaping no. is 4,5.