AtomicLongArray getAndSet() method in Java with Examples

The Java.util.concurrent.atomic.AtomicLongArray.getAndSet() is an inbuilt method in Java that atomically sets a given value at any given position of the AtomicLongArray. The method takes the index value of the AtomicLongArray and the value to set as the parameters. It returns the value at the given index before setting the new value at that index. The function getAndSet() is similar to the set() function but the former returns value while the latter does not return any value.
Syntax:

public final long getAndSet(int i, long newValue)

Parameters: The function accepts two parameters:

i – The index where update is to be made.

newValue – The value to set at index i

Return value: The function returns the value at the given index before the update which is in long.

Below programs illustrate the above method:

Program 1:

// Java program that demonstrates
// the getAndSet() function

import java.util.concurrent.atomic.AtomicLongArray;

public class GFG {
    public static void main(String args[])
    {
        // Initializing an array
        long a[] = { 11, 12, 13, 14, 15 };

        // Initializing an AtomicLongArray with array a
        AtomicLongArray arr = new AtomicLongArray(a);

        // Displaying the AtomicLongArray
        System.out.println("The array : " + arr);

        // Index where operation is performed
        int idx = 0;

        // New value to set at idx
        long val = 100;

        // Updating the value at
        // idx applying getAndSet
        // and store previous value
        long prev = arr.getAndSet(idx, val);

        // Previous value at idx before update
        System.out.println("Value at index " + idx
                           + " before the update is "
                           + prev);

        // Displaying the AtomicLongArray
        System.out.println("The array after update : "
                           + arr);
    }
}

Output:

The array : [11, 12, 13, 14, 15]
Value at index 0 before the update is 11
The array after update : [100, 12, 13, 14, 15]

Program 2:

// Java program that demonstrates
// the getAndSet() function

import java.util.concurrent.atomic.AtomicLongArray;

public class GFG {
    public static void main(String args[])
    {
        // Initializing an array
        long a[] = { 11, 12, 13, 14, 15 };

        // Initializing an AtomicLongArray with array a
        AtomicLongArray arr = new AtomicLongArray(a);

        // Displaying the AtomicLongArray
        System.out.println("The array : " + arr);

        // Index where operation is performed
        int idx = 3;

        // New value to set at idx
        long val = 10;

        // Updating the value at
        // idx applying getAndSet
        // and store previous value
        long prev = arr.getAndSet(idx, val);

        // Previous value at idx before update
        System.out.println("Value at index " + idx
                           + " before the update is "
                           + prev);

        // Displaying the AtomicLongArray
        System.out.println("The array after update : "
                           + arr);
    }
}

Output:

The array : [11, 12, 13, 14, 15]
Value at index 3 before the update is 14
The array after update : [11, 12, 13, 10, 15]

Reference:
https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/atomic/AtomicLongArray.html#getAndSet-int-long-