Set hashCode() method in Java with Examples

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

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 Set.

Below examples illustrates the Set.hashCode() method:

Example 1:

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

import java.util.*;

public class GFG {
    public static void main(String[] args)
    {
        // creating an Set
        Set<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 Set
        System.out.println("Set: " + arr);

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

Output:

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

Example 2:

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

import java.util.*;

public class GFG {
    public static void main(String[] args)
    {
        // creating an Set
        Set<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 Set
        System.out.println("Set: " + arr);

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

Output:

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

Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Set.html#hashCode()