swap()

Function

It is used to swap the elements at the specified positions in the specified list.

Declaration

public static void swap(List<?> list,int index1,int index2)	

Parameters

list - The list in which to the swap elements.

index1 - The index of first element to be swapped.

index2 - The index of the other element to be swapped.

If the elements with index numbers of index1 and index2 do not exist, the method throws ArrayIndexOutOfBoundsException.

Example

import java.util.*;
public class SwapExample
{
	public static void main(String args[])
	{
		ArrayList list = new ArrayList();
		list.add(50);
		list.add(10);
		list.add(20);
		list.add(40);
    		System.out.println("Before swapping: " +list);
		Collections.swap(list, 0,3);
		System.out.println("After swapping: " +list); 
	}
}

Output

Before swapping: [50, 10, 20, 40]
After swapping: [40, 10, 20, 50]