AbstractCollection contains() Method in Java with Examples

The contains() method of Java AbstractCollection is used to check whether an element is present in a Collection or not. It takes the element as a parameter and returns True if the element is present in the collection.
Syntax:

AbstractCollection.contains(Object element)

Parameters: The parameter element is of type Collection. This parameter refers to the element whose occurrence is needed to be checked in the collection.
Return Value: The method returns True if the element is present in the Collection otherwise it returns False.
Below programs illustrate the Java.util.AbstractCollection.contains() method:
Program 1:

Java

// Java code to illustrate boolean contains()

import java.util.*;
import java.util.AbstractCollection;

public 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");

        // Displaying the collection
        System.out.println("Abstract Collection:"
                           + abs);

        // Check if the collection contains "Hello"
        System.out.println("\nDoes the Collection"
                           + " contains 'Hello': "
                           + abs.contains("Hello"));

        // Check if the Collection contains "20"
        System.out.println("Does the collection"
                           + " contains '20': "
                           + abs.contains("20"));

        // Check if the Collection contains "Geeks"
        System.out.println("Does the Collection"
                           + " contains 'Geeks': "
                           + abs.contains("Geeks"));
    }
}

Output:

Abstract Collection:[Geeks, for, Geeks, 10, 20]

Does the Collection contains 'Hello': false
Does the collection contains '20': true
Does the Collection contains 'Geeks': true

Program 2:

Java

// Java code to illustrate boolean contains()

import java.util.*;
import java.util.AbstractCollection;

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

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

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

        // Displaying the collection
        System.out.println("Abstract Collection:"
                           + abs);

        // Check if the collection contains "TreeSet"
        System.out.println("\nDoes the Collection "
                           + "contains 'TreeSet': "
                           + abs.contains("TreeSet"));

        // Check if the collection contains "Hello"
        System.out.println("\nDoes the Collection"
                           + " contains 'Hello': "
                           + abs.contains("Hello"));

        // Check if the Collection contains "20"
        System.out.println("Does the collection"
                           + " contains '20': "
                           + abs.contains("20"));

        // Check if the Collection contains "Geeks"
        System.out.println("Does the Collection"
                           + " contains 'Geeks': "
                           + abs.contains("Geeks"));
    }
}

Output:

Abstract Collection:[20, Geeks, TreeSet, for]

Does the Collection contains 'TreeSet': true

Does the Collection contains 'Hello': false
Does the collection contains '20': true
Does the Collection contains 'Geeks': true