The addAll(Collection C) method of Java AbstractCollection is used to append all of the elements from a mentioned collection to this collection. The elements are added randomly without following any specific order.
Syntax:
boolean addAll(Collection C)
Parameters: The parameter C is a collection of any type that is to be added to the collection.
Return Value: The method returns true if it successfully appends the elements of the collection C to the existing collection otherwise it returns False.
Below programs illustrate the AbstractCollection.addAll() method:
Program 1:
Java
// Java code to illustrate addAll()// method of AbstractCollectionimport java.util.*;import java.util.AbstractCollection;public class AbstractCollectionDemo { public static void main(String args[]) { // Creating an empty collection AbstractCollection<String> abs1 = new TreeSet<String>(); // Use add() method to add // elements into the Collection abs1.add("Welcome"); abs1.add("To"); abs1.add("Geeks"); abs1.add("4"); abs1.add("Geeks"); abs1.add("TreeSet"); // Displaying the Collection System.out.println("AbstractCollection 1: " + abs1); // Creating another Collection AbstractCollection<String> abs2 = new TreeSet<String>(); // Displaying the Collection System.out.println("AbstractCollection 2: " + abs2); // Using addAll() method to Append abs2.addAll(abs1); // Displaying the Collection System.out.println("AbstractCollection 2: " + abs2); }} |
Output:
AbstractCollection 1: [4, Geeks, To, TreeSet, Welcome] AbstractCollection 2: [] AbstractCollection 2: [4, Geeks, To, TreeSet, Welcome]
Program 2:
Java
// Java code to illustrate addAll()// method of AbstractCollectionimport java.util.*;import java.util.AbstractCollection;public class AbstractCollectionDemo { public static void main(String args[]) { // Creating an empty collection AbstractCollection<Integer> abs1 = new TreeSet<Integer>(); // Use add() method to add // elements into the Collection abs1.add(10); abs1.add(20); abs1.add(30); abs1.add(40); abs1.add(50); // Displaying the Collection System.out.println("AbstractCollection 1: " + abs1); // Creating another Collection AbstractCollection<Integer> abs2 = new TreeSet<Integer>(); // Displaying the Collection System.out.println("AbstractCollection 2: " + abs2); // Using addAll() method to Append abs2.addAll(abs1); // Displaying the Collection System.out.println("AbstractCollection 2: " + abs2); }} |
Output:
AbstractCollection 1: [10, 20, 30, 40, 50] AbstractCollection 2: [] AbstractCollection 2: [10, 20, 30, 40, 50]
