This method appends all of the elements in the specified collection to the end of this list, in the order that they are returned by the specified collection’s iterator.
Syntax:
boolean addAll(Collection c)
Parameters: This function has a single parameter, i.e, Collection c, whose elements are to be appended to the list.
Returns: It returns true if the elements of specified list is appended and list changes.
Below programs show the implementation of this method.
Program 1:
// Java code to show the implementation of // addAll method in list interface import java.util.*; public class GfG { // Driver code public static void main(String[] args) { // Initializing a list of type arraylist List<Integer> l = new ArrayList<>(); l.add( 10 ); l.add( 15 ); l.add( 20 ); System.out.println(l); // Initializing a collection to be appended to list ArrayList<Integer> arr = new ArrayList<Integer>(); arr.add( 100 ); arr.add( 200 ); arr.add( 300 ); System.out.println(arr); l.addAll(arr); System.out.println(l); } } |
[10, 15, 20] [100, 200, 300] [10, 15, 20, 100, 200, 300]
Program 2: Below is the code to show implementation of list.addAll() using Linkedlist.
// Java code to show the implementation of // addAll method in list interface import java.util.*; public class GfG { // Driver code public static void main(String[] args) { // Initializing a list of type Linkedlist List<Integer> l = new LinkedList<>(); l.add( 10 ); l.add( 15 ); l.add( 20 ); System.out.println(l); // Initializing a collection to be appended to list ArrayList<Integer> arr = new ArrayList<Integer>(); arr.add( 100 ); arr.add( 200 ); arr.add( 300 ); System.out.println(arr); l.addAll(arr); System.out.println(l); } } |
[10, 15, 20] [100, 200, 300] [10, 15, 20, 100, 200, 300]
Reference:
Oracle Docs