Java Example : How To Swap Integer and String Variables Without Using a Temporary Variable

Hi guys,

Swapping two variable has always been a classic learning example for beginners, well for a change in the example below we would be learning to swap two variables (String or Integer) without using a temporary variable.

/*

  *   @(#)Swap.java       1.1   28/04/09

  *

  *   Copyright   2009   Lazy   Coder.   All   rights   reserved.

  *   To   be   used   only   for   educational   purposes.

  *   Not   to   be   reproduced   and   published

  *   without   seeking   prior   consent.

  */

package   com.lazy.coder.examples;





/**

  *   A   class   that   demonstrates   how   to   swap  

  *   two   strings   or   two   integers   without

  *   using   a   temporary   variable

  *  

  *   @author   lazycoder

  *  

  */

public   class   Swap   {



      

       /**

         *   @param   args

         */

       public   static   void   main(String[]   args)   {

              //Swapping   two   String   without   using   temp   variable.

              String   firstString   =   "Lazy";

              String   secondString   =   "LazyCoder";

              System.out.println("firstString   =   "   +   firstString);

              System.out.println("secondString   =   "   +   secondString);

              System.out.println("Swapping");

              firstString   =   firstString   +   secondString;

              secondString   =   firstString.substring(0,   firstString.length()

                            -   secondString.length());

              firstString   =   firstString.substring(secondString.length());

              System.out.println("firstString   =   "   +   firstString);

              System.out.println("secondString   =   "   +   secondString);

             

              //Swapping   two   Integers   without   using   temp   variable.

              int   firstInt   =   111111111;

              int   secondInt   =   999999999;

              System.out.println("firstInt   =   "   +   firstInt);

              System.out.println("secondInt   =   "   +   secondInt);

              System.out.println("Swapping");

              /*

                *   Using   exclusive-or   (XOR)   to   avoid  

                *   stack   overflow/underflow

                */

              firstInt   =   firstInt   ^   secondInt;

              secondInt   =   firstInt   ^   secondInt;

              firstInt   =   firstInt   ^   secondInt;

              System.out.println("firstInt   =   "   +   firstInt);

              System.out.println("secondInt   =   "   +   secondInt);

       }

}



Thats all for now, check back for more java examples.

Lazy Coder
signing off for now...