ArrayDeque.removeIf(Predicate) in Java

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

Syntax:

boolean java.util.ArrayDeque.removeIf(Predicate<? super E> filter)

This method takes one argument. This method removes all of the elements of this collection that satisfy the given predicate.

Parameters: One parameter is required for this method.

filter: a predicate which returns true for elements to be removed.

Returns: true if any elements were removed.

Throws:

NullPointerException - if the specified filter is null.

Approach 1: When no exception

Java

import java.util.ArrayDeque;

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

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

        arrayDeque.add(1);
        arrayDeque.add(4);
        arrayDeque.add(11);
        arrayDeque.add(41);

        arrayDeque.removeIf(n -> n % 2 == 0);
        System.out.println(arrayDeque.clone());

    }
}

Output:

[1, 11, 41]

Approach 2: NullPointerException 

Java

import java.util.ArrayDeque;

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

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

        arrayDeque.add(1);
        arrayDeque.add(4);
        arrayDeque.add(11);
        arrayDeque.add(41);

        arrayDeque.removeIf(null);
        System.out.println(arrayDeque.clone());

    }
}

Output:

Exception in thread "main" java.lang.NullPointerException
	at java.base/java.util.Objects.requireNonNull(Objects.java:208)
	at java.base/java.util.ArrayDeque.removeIf(ArrayDeque.java:900)