AbstractCollection containsAll() Method in Java with Examples

The containsAll() method of Java AbstractCollection is used to check whether two Collections contain the same elements or not. It takes one collection as a parameter and returns True if all of the elements of this collection is present in the other collection.

Syntax:

AbstractCollection.containsAll(Collection C)

Parameters: The parameter C is a Collection. This parameter refers to the collection whose elements occurrence is needed to be checked in this collection.

Return Value: The method returns True if this collection contains all the elements of other Collection otherwise it returns False.

Below programs illustrate the AbstractCollection.conatinsAll() method:

Program 1:

// Java code to illustrate boolean containsAll()

import java.util.*;

class AbstractCollectionDemo {
    public static void main(String args[])
    {

        // Creating an empty Collection
        AbstractCollection<String>
            abs = new LinkedList<String>();

        // Use add() method to
        // add elements in the collection
        abs.add("Geeks");
        abs.add("for");
        abs.add("Geeks");
        abs.add("10");
        abs.add("20");

        // Creating another empty Collection
        AbstractCollection<String>
            abs2 = new LinkedList<String>();

        // Use add() method to
        // add elements in the collection
        abs2.add("Geeks");
        abs2.add("for");
        abs2.add("Geeks");
        abs2.add("10");
        abs2.add("20");

        // Check if the collection
        // contains same elements
        System.out.println("\nBoth the collections same: "
                           + abs.containsAll(abs2));
    }
}

Output:

Both the collections same: true

Program 2:

// Java code to illustrate boolean containsAll()

import java.util.*;

class AbstractCollectionDemo {
    public static void main(String args[])
    {

        // Creating an empty Collection
        AbstractCollection<String>
            abs = new LinkedList<String>();

        // Use add() method to
        // add elements in the collection
        abs.add("Geeks");
        abs.add("for");
        abs.add("Geeks");

        // Creating another empty Collection
        AbstractCollection<String>
            abs2 = new LinkedList<String>();

        // Use add() method to
        // add elements in the collection
        abs2.add("10");
        abs2.add("20");

        // Check if the collection
        // contains same elements
        System.out.println("\nBoth the collections same: "
                           + abs.containsAll(abs2));
    }
}

Output:

Both the collections same: false