Java ArrayList isEmpty()

Introduction

In Java, the ArrayList class is a commonly used implementation of the List interface, which provides a dynamic array-like data structure. The isEmpty() method is a member of this class that returns a boolean value indicating whether the ArrayList is empty or not. This method is quite useful when you want to check if the list contains any elements before performing further operations.

Syntax

The syntax for isEmpty() method is:

public boolean isEmpty()

Return Value

The isEmpty() method returns a boolean value:

• true if the ArrayList is empty and contains no elements.
• false if the ArrayList contains one or more elements.

Example

Here is an example that demonstrates the usage of isEmpty() method:

import java.util.ArrayList;

public class ArrayListExample {
    public static void main(String[] args) {
        ArrayList<String> fruits = new ArrayList<>();

        System.out.println("Is the ArrayList empty? " + fruits.isEmpty()); // Output: Is the ArrayList empty? true

        fruits.add("Apple");
        fruits.add("Banana");

        System.out.println("Is the ArrayList empty? " + fruits.isEmpty()); // Output: Is the ArrayList empty? false
    }
}

In this example, we first create an empty ArrayList called fruits. We then use the isEmpty() method to check if the list is empty and print the result. As expected, the output is true. After adding two elements to the ArrayList, we again use the isEmpty() method to check if the list is empty. This time, the output is false.

Conclusion

The isEmpty() method of the ArrayList class in Java is a convenient way to check if the list is empty or not. By using this method, you can avoid potential errors when trying to access or manipulate elements in an empty list.