The weakCompareAndSetVolatile() method of a AtomicReference class is used to atomically sets the value to newValue for AtomicReference if the current value is equal to expectedValue passed as parameter. This method updates the value with memory effects as specified by VarHandle.weakCompareAndSet(java.lang.Object…). This method returns true if set a new value to AtomicReference is successful. Syntax:
public final boolean
weakCompareAndSetVolatile(V expectedValue,
V newValue)
Parameters: This method accepts expectedValue which is the expected value and newValue which is the new value to set. Return value: This method returns true if successful. Below programs illustrate the weakCompareAndSetVolatile() method: Program 1:
Java
// Java program to demonstrate// AtomicReference.weakCompareAndSetVolatile() methodimport java.util.concurrent.atomic.AtomicReference;public class GFG { public static void main(String[] args) { // create an atomic reference object. AtomicReference<Double> ref = new AtomicReference<Double>(); // set some value ref.set(1234.00); // apply weakCompareAndSetVolatile() boolean result = ref.weakCompareAndSetVolatile(124.00, 234.32); // print value System.out.println("Setting new value" + " is successful = " + result); System.out.println("Value = " + ref.get()); }} |
Output: 
Program 2:
Java
// Java program to demonstrate// AtomicReference.weakCompareAndSetVolatile() methodimport java.util.concurrent.atomic.AtomicReference;public class GFG { public static void main(String[] args) { // create an atomic reference object which stores String. AtomicReference<String> ref = new AtomicReference<String>(); // set some value ref.set("GFG"); // apply weakCompareAndSetVolatile() boolean result = ref.weakCompareAndSetVolatile( "GFG", "GEEKS FOR GEEKS"); // print value System.out.println("Setting new value" + " is successful = " + result); System.out.println("Value = " + ref.get()); }} |
Output:
