In this example we shall show you how to replace all elements of a List. We will use the fill(List list, Object element) API method of the Collections class. Collections provides static methods that operate on or return collections. The ArrayList is used as a List implementation, but the same API applies to any type of List implementation classes e.g. Vector etc. To replace all elements of a List one should perform the following steps:
- Create a new ArrayList.
- Populate the list with elements, with the
add(E e)API method of the ArrayList. - Invoke the
fill(List list, Object element)API method of Collections. It will replace all elements of the provided list with the specified element,
as described in the code snippet below.
package com.javacodegeeks.snippets.core;
import java.util.ArrayList;
import java.util.Collections;
public class ReplaceAllElementsOfList {
public static void main(String[] args) {
/*
Please note that the same API applies to any type of
List implementation classes e.g. Vector etc
*/
// Create an ArrayList and populate it with elements
ArrayList arrayList = new ArrayList();
arrayList.add("element_1");
arrayList.add("element_2");
arrayList.add("element_3");
System.out.println("ArrayList elements : " + arrayList);
// static void fill(List list, Object element) operation replaces all elements of the provided List with the specified element
Collections.fill(arrayList,"element_4");
System.out.println("ArrayList elements after replacement with element_4 : " + arrayList);
}
}
Output:
ArrayList elements : [element_1, element_2, element_3]
ArrayList elements after replacement with element_4 : [element_4, element_4, element_4]
This was an example of how to replace all elements of a List in Java.
