ArrayDeque.forEach(Consumer) in Java

ArrayDeque.forEach(Consumer<? super E>): This method is available in java.util.ArrayDeque class of Java.

Syntax:

void java.util.ArrayDeque.forEach(Consumer<? super E> action)

This method takes one argument. This method performs the given action for each element of the Iterable until all elements have been processed or the action throws an exception.

Parameters: One parameter is required for this method.

action: The action to be performed for each element.

Returns: NA

Throws:

NullPointerException - if the specified action is null

Approach 1: When no exception

Java

import java.util.ArrayDeque;

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

        ArrayDeque<Integer> arrayDeque = 
                          new ArrayDeque<Integer>();

        arrayDeque.add(1);
        arrayDeque.add(4);

        arrayDeque.forEach((n -> System.out.print(n + " ")));

    }
}

Output:

1 4 

Approach 2: NullPointerException 

Java

import java.util.ArrayDeque;

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

        ArrayDeque<Integer> arrayDeque =
                      new ArrayDeque<Integer>();

        arrayDeque.add(1);
        arrayDeque.add(4);

        arrayDeque.forEach(null);

    }
}

Output:

Exception in thread "main" java.lang.NullPointerException
	at java.base/java.util.Objects.requireNonNull(Objects.java:208)
	at java.base/java.util.ArrayDeque.forEach(ArrayDeque.java:883)