OptionalInt equals() method in Java with examples

OptionalInt help us to create an object which may or may not contain a Int value. The equals(Object obj) method help us to compare this OptionalInt object with the passed object as a parameter and it returns true if objects are equal.

The other object is considered equal to this OptionalInt if:

• it is also an OptionalInt and;
• both instances have no value present or;
• the present values are “equal to” each other via ==.

Syntax:

public boolean equals(Object obj)

Parameters: This method accepts an obj which is an object to be tested for equality.

Return value: This method returns true if the other object is “equal to” this object otherwise false.

Below programs illustrate equals(Object obj) method:

Program 1:

// Java program to demonstrate
// OptionalInt.equals(Object obj) method

import java.util.OptionalInt;

public class GFG {

    public static void main(String[] args)
    {

        // Create first OptionalInt object
        OptionalInt opInt1
            = OptionalInt.of(7258);

        System.out.println("OptionalInt 1: "
                           + opInt1.toString());

        // Create second OptionalInt object
        OptionalInt opInt2
            = OptionalInt.of(7258);

        System.out.println("OptionalInt 2: "
                           + opInt2.toString());

        // Check if these two objects are equal
        // using equals(Object obj)
        System.out.println("Are both objects equal: "
                           + opInt1.equals(opInt2));
    }
}

Output:

OptionalInt 1: OptionalInt[7258]
OptionalInt 2: OptionalInt[7258]
Are both objects equal: true

Program 2:

// Java program to demonstrate
// OptionalInt.equals(Object obj) method

import java.util.OptionalInt;

public class GFG {

    public static void main(String[] args)
    {
        // Create first OptionalInt object
        OptionalInt opInt1
            = OptionalInt.of(5422);

        System.out.println("OptionalInt 1: "
                           + opInt1.toString());

        // Create second OptionalInt object
        OptionalInt opInt2
            = OptionalInt.of(2737);

        System.out.println("OptionalInt 2: "
                           + opInt2.toString());

        // Check if these two objects are equal
        // using equals(Object obj)
        System.out.println("Are both objects equal: "
                           + opInt1.equals(opInt2));
    }
}

Output:

OptionalInt 1: OptionalInt[5422]
OptionalInt 2: OptionalInt[2737]
Are both objects equal: false

References: https://docs.oracle.com/javase/10/docs/api/java/util/OptionalInt.html#equals?(Object obj)