Remove null values from an ArrayList in Java

In this tutorial we will learn about Remove null values from an ArrayList in Java with some cool and easy examples.

Remove null values from an ArrayList in Java

To remove null values from an `ArrayList` in Java, you can iterate through the list and remove any null elements you encounter. Here's a straightforward approach:

import java.util.ArrayList;
import java.util.Iterator;

public class RemoveNullValues {
    public static void main(String[] args) {
        // Create an ArrayList with some elements including null
        ArrayList<String> list = new ArrayList<>();
        list.add("Apple");
        list.add(null);
        list.add("Banana");
        list.add(null);
        list.add("Orange");

        // Print the ArrayList before removing null values
        System.out.println("ArrayList before removing null values: " + list);

        // Remove null values
        Iterator<String> iterator = list.iterator();
        while (iterator.hasNext()) {
            if (iterator.next() == null) {
                iterator.remove();
            }
        }

        // Print the ArrayList after removing null values
        System.out.println("ArrayList after removing null values: " + list);
    }
}

In this code:

– We create an `ArrayList` named `list` and add some elements including `null`.
– We iterate through the list using an `Iterator`.
– Inside the loop, we check if the current element is `null` and if so, we remove it using the `Iterator.remove()` method.
– After iterating through the list, all `null` values are removed.
– We print the `ArrayList` before and after removing the null values to verify the result.

This approach ensures that the elements are removed safely from the `ArrayList` without causing any concurrent modification exceptions.

Benefits:

• Efficiency: Removing elements using an Iterator is more efficient than modifying the ArrayList directly, especially when dealing with large collections.
• Safety: Using an Iterator ensures safe removal of elements while iterating over the collection.
• Flexibility: This approach can be applied to remove null values from ArrayLists containing any type of elements, not just strings.

Output:

ArrayList before removing null values: [Apple, null, Banana, null, Orange]
ArrayList after removing null values: [Apple, Banana, Orange]