OptionalInt orElseGet() method in Java with examples

The orElseGet(java.util.function.IntSupplier) method helps us to get the value in this OptionalInt object. If a value is not present in this OptionalInt, then this method returns the result produced by the supplying function, passed as the parameter

Syntax:

public int orElseGet(IntSupplier supplier)

Parameters: This method accepts the supplying function that produces a value to be returned.

Return value: This method returns the int value, if present, otherwise the result produced by the supplying function.

Exception: This method throw NullPointerException if no value is present and the supplying function is null.

Below programs illustrate orElseGet(java.util.function.IntSupplier) method:

Program 1:

// Java program to demonstrate
// OptionalInt.orElseGet(IntSupplier) method

import java.util.OptionalInt;

public class GFG {

    public static void main(String[] args)
    {

        // create a OptionalInt
        OptionalInt opint = OptionalInt.of(2134);

        // get value using orElseGet
        int value = opint.orElseGet(() -> getintValue());

        // print value
        System.out.println("value: " + value);
    }

    public static int getintValue()
    {
        return 3242 + 123;
    }
}

Output:

value: 2134

Program 2:

// Java program to demonstrate
// OptionalInt.orElseGet(IntSupplier) method

import java.util.OptionalInt;

public class GFG {

    public static void main(String[] args)
    {

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

        // get value using orElseGet
        int value = opint.orElseGet(() -> getintValue());

        // print value
        System.out.println("value: " + value);
    }

    public static int getintValue()
    {
        return 3242 * 234;
    }
}

Output:

value: 758628

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