Set hashCode() method in Java with Examples

Last Updated : 31 Dec, 2018

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()

Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more, please refer Complete Interview Preparation Course.

My Personal Notes

Related Articles

Set hashCode() method in Java with Examples