JAVASCRIPT

swapping elements in an array

let a = 1;
let b = 3;

[a, b] = [b, a]; // destructuring assignment, assigning the value of a and b to a new array created with b and a
console.log(a); // 3
console.log(b); // 1

const arr = [1,2,3];
[arr[2], arr[1]] = [arr[1], arr[2]];
console.log(arr); // [1,3,2]

swap in array

import java.util.Arrays;

public class swapInArray {

    public static void main (String[] args) {
                int[] arr = {1,10,100,1000};
                swap(arr,1,3);
                System.out.println(Arrays.toString(arr));
            }

            private static void swap (int[] arr, int index1, int index2){
                int elem1 = arr[index1];
                int elem2 = arr[index2];
                arr[index1] = elem1;
                arr[index2] = elem2;
    }
}