Arrays.parallelSetAll(int[], IntUnaryOperator) in Java

Arrays.parallelSetAll(int[], IntUnaryOperator): This method is available in java.util.Arrays class of Java.

Syntax:

void java.util.Arrays.parallelSetAll(int[] array, IntUnaryOperator generator)

This method takes two arguments one of type int array and the other of type IntUnaryOperator as its parameters. This method sets all elements of the specified array, in parallel, using the provided generator function to compute each element.

Note: If the generator function throws an exception, an unchecked exception is thrown from parallelSetAll and the array is left in an indeterminate state.

Parameters: Two parameters are required for this method.

array: array to be initialized generator a function accepting an index and producing the desired value for that position.

Throws:

NullPointerException - if the generator is null.

Approach 1: When no exceptions

Java

import java.util.Arrays;
import java.util.function.IntUnaryOperator;

public class ArraysparallelSetAllint {
    public static void main(String[] args) {

        int array[] = { 12, 34, 56, 78 };

        IntUnaryOperator generator = intVal -> {
            int doubleVal = intVal;
            return doubleVal;
        };

        Arrays.parallelSetAll(array, generator);

        System.out.println(Arrays.toString(array));
    }
}

Output:

[0, 1, 2, 3]

Approach 2: NullPointerException 

Java

import java.util.Arrays;
import java.util.function.IntUnaryOperator;

public class ArraysparallelSetAllint {
    public static void main(String[] args) {

        int array[] = { 12, 34, 56, 78 };

        IntUnaryOperator generator = null;

        Arrays.parallelSetAll(array, generator);

        System.out.println(Arrays.toString(array));
    }
}

Output:

Exception in thread "main" java.lang.NullPointerException
	at java.base/java.util.Objects.requireNonNull(Objects.java:208)
	at java.base/java.util.Arrays.parallelSetAll(Arrays.java:5144)