Java program to swap two numbers

Let’s learn java program to swap two numbers.

Java program to swap two numbers

Well, there are few ways to swap two numbers in java,

  1. with temporary variable
  2. without temporary variable

Let’s see java program to swapping two numbers using a temporary variable,

import java.util.Scanner;

public class SwapTwoNumbersInJava
{
   public static void main(String[] args)
   {
      int a;
      int b;
      int swap;
      System.out.println("Please enter two integers to swap : ");
      Scanner sc = new Scanner(System.in);
      a = sc.nextInt();
      b = sc.nextInt();
      System.out.println("Before swap : a = " + a + "\nBefore swap : b = " + b);
      swap = a;
      a = b;
      b = swap;
      System.out.println("After swap : a = " + a + "\nAfter swap : b = " + b);
   }
}



Output:

java program to swap two numbers

// how to swap two numbers without using a temporary variable

import java.util.Scanner;

public class SwapTwoNumbers
{
   public static void main(String[] args)
   {
      int a;
      int b; 
      System.out.println("Please enter two integers to swap : ");
      Scanner sc = new Scanner(System.in);
      a = sc.nextInt();
      b = sc.nextInt();
      System.out.println("Before swap : a = " + a + "\nBefore swap : b = " + b);
      a = a + b;
      b = a - b;
      a = a - b;
      System.out.println("After swap : a = " + a + "\nAfter swap : b = " + b);
   }
}



Output:

Please enter two integers to swap : 10 5
Before swap : a = 10
Before swap : b = 5
After swap : a = 5
After swap : b = 10


Also read – preface to java virtual machine and architecture