Replacing Elements with the set() method: public Object set(int index, Object element) : ArrayList « Collections « Java Tutorial

1. Java Tutorial
2. Collections
3. ArrayList

The object being replaced is returned by the set() method.

import java.util.Arrays;
import java.util.List;
public class MainClass {
  public static void main(String[] a) {
    List list = Arrays.asList(new String[] { "A", "B", "C", "D" });
    list.set(2, "X");
    System.out.println(list);
  }
}

[A, B, X, D]