import java.util.ArrayList;
import java.util.Collections;
import java.util.Arrays;
public class MyClass {
public static void main(String args[]) {
ArrayList<Integer> al = new ArrayList<>(Arrays.asList(40, 89, 23, 99, 89));
System.out.println(al);
Collections.swap(al, 0, 2);
System.out.println(al);
}
}
/*
run:
[40, 89, 23, 99, 89]
[23, 89, 40, 99, 89]
*/