.swap()
The Collections.swap()
method swaps the positions of two elements in a List
.
Syntax
import java.util.*;
Collections.swap(myList, index1, index2);
This will swap the element in myList
at zero-based int
index index1
with the element at zero-based int
index index2
.
Example
The following example creates an ArrayList
and then uses Collections.swap()
to reorder some elements:
import java.util.*;public class Main {public static void main(String[] args) {ArrayList<String> food = new ArrayList<String>();food.add("Cabbage");food.add("Pizza");food.add("Sausage");food.add("Potatoes");food.add("Salad");System.out.println(food);Collections.swap(food,2,4);System.out.println(food);}}
This will output the following:
[Cabbage, Pizza, Sausage, Potatoes, Salad][Cabbage, Pizza, Salad, Potatoes, Sausage]