The getAndUpdate() method of a AtomicReferenceArray class is used to atomically updates which updates the current value of the AtomicReferenceArray by applying the specified updateFunction operation on the current value. It takes an object of updateFunction interface as its parameter and applies the operation specified in the object to the current value. It returns the previous value.
Syntax:
public final E
getAndUpdate(int i,
UnaryOperator<E> updateFunction)
Parameters: This method accepts:
- index i to update the index value and
- updateFunction which is a side-effect-free function.
Return value: This method returns the previous value.
Below programs illustrate the getAndUpdate() method:
Program 1:
Java
// Java program to demonstrate// AtomicReferenceArray.getAndUpdate() methodimport java.util.concurrent.atomic.*;import java.util.function.UnaryOperator;public class GFG { public static void main(String args[]) { // an array String a[] = { "GFG", "JS", "PYTHON", "JAVA" }; // AtomicReferenceArray with array AtomicReferenceArray<String> array = new AtomicReferenceArray<>(a); // Print AtomicReferenceArray System.out.println( "The AtomicReferenceArray before update : " + array); // Index int index = 2; // Declaring the accumulatorFunction // applying function UnaryOperator add = (u) -> u.toString() + " and ML"; // apply getAndUpdate() String value = array.getAndUpdate(index, add); // print AtomicReferenceArray System.out.println("previous value of index 2:" + value); System.out.println("The AtomicReferenceArray " + "after update: " + array); }} |
Output:
Program 2:
Java
// Java program to demonstrate// AtomicReferenceArray.getAndUpdate() methodimport java.util.concurrent.atomic.*;import java.util.function.UnaryOperator;public class GFG { public static void main(String args[]) { // an array Integer a[] = { 213, 1234, 4543, 345 }; // AtomicReferenceArray with array AtomicReferenceArray<Integer> array = new AtomicReferenceArray(a); // Print AtomicReferenceArray System.out.println( "The AtomicReferenceArray" + " before update : " + array); // Index int index = 2; // Declaring the accumulatorFunction // applying function UnaryOperator add = (u) -> Integer.parseInt(u.toString()) * 200; // apply getAndUpdate() int value = array.getAndUpdate(index, add); // print AtomicReferenceArray System.out.println("previous value of index 2:" + value); System.out.println("updated value of index 2:" + array.get(2)); System.out.println("The AtomicReferenceArray " + "after update: " + array); }} |
Output: