OptionalInt hashCode() method in Java with examples

The hashCode() method help us to get the hash code of the value, if Int value is present, otherwise 0 (zero) if no Int value is present in OptionalInt object.

Syntax:

public int hashCode()

Parameters: This method accepts does not accepts any parameter.

Return value: This method returns hash code value of the present value or 0 if no value is present.

Below programs illustrate hashCode() method:

Program 1:

// Java program to demonstrate
// OptionalInt.hashCode() method

import java.util.OptionalInt;

public class GFG {

    public static void main(String[] args)
    {

        // create a OptionalInt instance
        OptionalInt opInt
            = OptionalInt.of(253);

        System.out.println("OptionalInt: "
                           + opInt.toString());

        // get hashCode value using hashCode()
        System.out.println("HashCode value: "
                           + opInt.hashCode());
    }
}

Output:

OptionalInt: OptionalInt[253]
HashCode value: 253

Program 2:

// Java program to demonstrate
// OptionalInt.hashCode() method

import java.util.OptionalInt;

public class GFG {

    public static void main(String[] args)
    {

        // create a OptionalInt instance
        OptionalInt opInt
            = OptionalInt.empty();

        System.out.println("OptionalInt: "
                           + opInt.toString());

        // get hashCode value using hashCode()
        System.out.println("HashCode value: "
                           + opInt.hashCode());
    }
}

Output:

OptionalInt: OptionalInt.empty
HashCode value: 0

References: https://docs.oracle.com/javase/10/docs/api/java/util/OptionalInt.html#hashCode()