OptionalInt ifPresent(IntConsumer) method in Java with examples

The ifPresentOrElse(java.util.function.IntConsumer) method helps us to perform the specified IntConsumer action the value of this OptionalInt object. If a value is not present in this OptionalInt, then this method does nothing.

Syntax:

public void ifPresentOrElse(IntConsumer action)

Parameters: This method accepts a parameter action which is the action to be performed on this Optional, if a value is present.

Return value: This method returns nothing.

Exception: This method throw NullPointerException if a value is present and the given action is null.

Below programs illustrate ifPresent(IntConsumer) method:

Program 1:

// Java program to demonstrate
// OptionalInt.ifPresent(IntConsumer) method

import java.util.OptionalInt;

public class GFG {

    public static void main(String[] args)
    {

        // create a OptionalInt
        OptionalInt opint = OptionalInt.of(2234);

        // apply ifPresent(IntConsumer)
        opint.ifPresent((value) -> {
            value = value * 2;
            System.out.println("Value after modification:=> "
                               + value);
        });
    }
}

Output:

Program 2:

// Java program to demonstrate
// OptionalInt.ifPresent(IntConsumer) method

import java.util.OptionalInt;

public class GFG {

    public static void main(String[] args)
    {

        // create a OptionalInt
        OptionalInt opint = OptionalInt.empty();

        // apply ifPresent(IntConsumer)
        opint.ifPresent((value) -> {
            value = value * 2;
            System.out.println("Value after modification:=> "
                               + value);
        });

        System.out.println("As OptionalInt is empty value"
                           + " is not modified");
    }
}

Output:

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