HashSet hashCode() method in Java with Example

The hashCode() method of HashSet in Java is used to get the hashCode value for this instance of the HashSet. It returns an integer value which is the hashCode value for this instance of the HashSet.

Syntax:

public int hashCode()

Parameters: This function has no parameters.

Returns: The method returns an integer value which is the hashCode value for this instance of the HashSet.

Below examples illustrates the HashSet.hashCode() method:

Example 1:

// Java code to demonstrate the working of
// hashCode() method in HashSet

import java.util.*;

public class GFG {
    public static void main(String[] args)
    {
        // creating an HashSet
        HashSet<Integer> arr
            = new HashSet<Integer>();

        // using add() to initialize values
        // [1, 2, 3, 4]
        arr.add(1);
        arr.add(2);
        arr.add(3);
        arr.add(4);

        // print HashSet
        System.out.println("HashSet: "
                           + arr);

        // Get the hashCode value
        // using hashCode() value
        System.out.println("HashCode value: "
                           + arr.hashCode());
    }
}

Output:

HashSet: [1, 2, 3, 4]
HashCode value: 10

Example 2:

// Java code to demonstrate the working of
// hashCode() method in HashSet

import java.util.*;

public class GFG {
    public static void main(String[] args)
    {
        // creating an HashSet
        HashSet<String> arr
            = new HashSet<String>();

        // using add() to initialize values
        // [Geeks, For, ForGeeks, GeeksForGeeks]
        arr.add("Geeks");
        arr.add("For");
        arr.add("ForGeeks");
        arr.add("GeeksForGeeks");

        // print HashSet
        System.out.println("HashSet: "
                           + arr);

        // Get the hashCode value
        // using hashCode() value
        System.out.println("HashCode value: "
                           + arr.hashCode());
    }
}

Output:

HashSet: [ForGeeks, Geeks, For, GeeksForGeeks]
HashCode value: -482506029