[^ Test which swapping method is the best ^]

				
//**************************************
// Name: [^ Test which swapping method is the best ^]
// Description:When you run this program it will show you which method of swapping two variables is the best (using XOR, a third temporary variable, or the Addition/Subtraction method) so your programs can use the most optimized technique.
// By: Donny Nadolny
//
// Returns:Shows the time (in millaseconds) to swap using 4 different techniques
//
// Assumes:All you need to do is run the program and read the output.
//
//This code is copyrighted and has// limited warranties.Please see http://www.Planet-Source-Code.com/vb/scripts/ShowCode.asp?txtCodeId=3824&lngWId=2//for details.//**************************************

/*
 * This class will test how fast the different ways of swapping variables are.
 * You can then choose the best way of swapping to get the best speed.
 * Made by Donny Nadolny (just the code to test these different ways of swapping,
 * the swapping methods themselves weren't made by me)
 *
 * On my computer (AMD Athlon 1.6GHz), the times are as follows:
 * 1. 390 ms - Swapping using a temp variable where it's declared once
 * 2. 421 ms - Swapping using a temp variable where it's declared each swap
 * 3. 581 ms - Swapping using the XOR way
 * 4. 691 ms - Swapping using the adition/subtraction way
 *
 * Note that these may vary depending on your computer speed and what programs are open.
 */
public class TestSwap
{
public static void main (String [] args)
{
//Number of times to swap
int times = 5000000;
//First int to swap
int variable1 = 5;
//Second int to swap
int variable2 = 6;
//The time (in millaseconds) before the variables were swapped
long before;
//The time (in millaseconds) after the variables were swapped
long after;
before = System.currentTimeMillis ();
//Swap them many times using the XOR way
for (int i = 0 ; i < times ; i++)
{
variable1 ^= variable2;
variable2 ^= variable1;
variable1 ^= variable2;
}
after = System.currentTimeMillis ();
//Print out how long it took
System.out.println ("It takes " + (after - before) + " milaseconds to swap variables using the XOR method.");
before = System.currentTimeMillis ();
//Swap many times using a temporary variable where it's declared each swap
for (int i = 0 ; i < times ; i++)
{
int tempVariable;
tempVariable = variable1;
variable1 = variable2;
variable2 = tempVariable;
}
after = System.currentTimeMillis ();
//Print out how long it took
System.out.println ("It takes " + (after - before) + " milaseconds to swap variables using a temporary variable where the variable is declared each time it is used to swap.");
before = System.currentTimeMillis ();
//Create a temporary variable once
int tempVariable;
//Swap using the temporary variable where it's declared only once
for (int i = 0 ; i < times ; i++)
{
tempVariable = variable1;
variable1 = variable2;
variable2 = tempVariable;
}
after = System.currentTimeMillis ();
//Print out how long it took
System.out.println ("It takes " + (after - before) + " milaseconds to swap variables using a temporary variable where the variable is declared once and used to swap many times.");
before = System.currentTimeMillis ();
//Swap using the addition/subtraction way many times
for (int i = 0 ; i < times ; i++)
{
variable1 += variable2;
variable2 = variable1 - variable2;
variable1 -= variable2;
}
after = System.currentTimeMillis ();
//Print out how long it took
System.out.println ("It takes " + (after - before) + " milaseconds to swap variables using the adition/subtraction method.");
}
}