AbstractSet contains() method in Java with Example

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

Syntax:

public boolean contains(Object element)

Parameters: The parameter element is of type set. This parameter refers to the element whose occurrence is needed to be checked in the set.

Return Value: The method returns a boolean value. It returns True if the element is present in the set otherwise it returns False.

Below programs illustrate the AbstractSet.contains() method:

Program 1:

// Java code to illustrate
// AbstractSet.contains()

import java.util.*;

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

        // Creating an empty set
        AbstractSet<String>
            abs = new TreeSet<String>();

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

        // Displaying the set
        System.out.println("AbstractSet: "
                           + abs);

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

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

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

Output:

AbstractSet: [10, 20, Geeks, for]

Does the set contains 'Hello': false
Does the set contains '20': true
Does the set contains 'Geeks': true

Program 2:

// Java code to illustrate
// AbstractSet.contains()

import java.util.*;

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

        // Creating an empty set
        AbstractSet<Integer>
            abs = new TreeSet<Integer>();

        // Use add() method to add
        // elements in the set
        abs.add(10);
        abs.add(20);
        abs.add(30);
        abs.add(40);
        abs.add(50);

        // Displaying the set
        System.out.println("AbstractSet:"
                           + abs);

        // Check if the set contains 10
        System.out.println("\nDoes the set "
                           + "contains '10': "
                           + abs.contains(10));

        // Check if the set contains 50
        System.out.println("\nDoes the set"
                           + " contains '50': "
                           + abs.contains(50));

        // Check if the set contains 100
        System.out.println("Does the set"
                           + " contains '100': "
                           + abs.contains(100));
    }
}

Output:

AbstractSet:[10, 20, 30, 40, 50]

Does the set contains '10': true

Does the set contains '50': true
Does the set contains '100': false