AtomicLong updateAndGet() method in Java with Examples

The Java.AtomicLong.updateAndGet() method is an inbuilt method, which updates the current value of the object by applying the specified operation on the current value. It takes an object of LongUnaryOperator interface as its parameter and applies the operation specified in the object to the current value. It returns the updated value.

Syntax:

public final long updateAndGet(LongUnaryOperator function)

Parameters: This method accepts as parameter an LongUnaryOperator function. It applies the given function to the current value of the object.

Return Value: The function returns the updated value of the current object.

Example to demonstrate the function.

Java

// Java program to demonstrate
// AtomicLong updateAndGet() method

import java.util.concurrent.atomic.AtomicLong;
import java.util.function.LongUnaryOperator;

public class Demo {
    public static void main(String[] args)
    {
        // AtomicLong initialized with a value of -20000
        AtomicLong al = new AtomicLong(-20000);

        // Unary operator defined to negate the value
        LongUnaryOperator unaryOperator = (x) -> - x;

        System.out.println("Initial Value is " + al);

        // Function called and the unary operator
        // is passed as an argument
        long x = al.updateAndGet(unaryOperator);
        System.out.println("Updated value is " + x);
    }
}

Output:

Initial Value is -20000
Updated value is 20000

Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/atomic/AtomicLong.html