How do I Remove Null Elements From An ArrayList In Java?

Today we will learn How to I Remove Null Elements From An ArrayList In Java? It can be done either by Iterator or simply by using remove if and passing a predicate.

Ways Remove Null Values From A Array List

There are ways to perform it and here we will discuss both of them one by one where we have to remove all the null values from a list or we can say all the elements which are string nothing or we can say empty elements.

Using Iterator

It is a way where we will iterate the whole array list one by one means all the elements of the arraylist one by one check the condition Whenever we find a null value just perform a removal of it. In this way, we can remove all the null values let’s see how it works.

for (Iterator<String> itr = words.iterator(); itr.hasNext(); ) {
    if (itr.next().isBlank()) {
        itr.remove();
    }
}

// while-loop version
Iterator<String> itr = words.iterator();
while (itr.hasNext()) {
    if (itr.next().isBlank()) {
        itr.remove();
    }
}

Here we can see how each element is checked and then removal takes place.

Now let’s understand another method

Remove If And Passing A Predicate

In this, we have used an inbuild function removeif() which removes all the spaces in between two elements or we can say if there are any blank elements it will remove them and it continues to do so until it comes to an end.

words.removeIf(new Predicate<>() {
    @Override public boolean test(String word) {
        return word.isBlank();
    }
});

// lambda "block" version
words.removeIf(word -> {
    return word.isBlank();
});

// single-expression lambda version
words.removeIf(word -> word.isBlank());

// method reference version
words.removeIf(String::isBlank);

Visit To learn more about removing null values from a list using different ways

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