ArrayList isEmpty() Method in Java with Examples (original) (raw)

Last Updated : 11 Dec, 2024

In Java, the **isEmpty() method of ArrayList is used to check if an ArrayList is empty.

**Example 1: Here, we use the **isEmpty() method **to check whether an ArrayList of integers is empty.

Java `

// Java program to demonstrate the use of isEmpty() // method with ArrayList of Integers import java.util.ArrayList;

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

    // Creating an empty ArrayList of Integers
    ArrayList<Integer> n = new ArrayList<>();

    // Checking if the ArrayList is empty
    boolean res = n.isEmpty();

    System.out.println("" + res);

    // Adding an element 
    // to the ArrayList
    n.add(21);

    // Checking again if the 
    // ArrayList is empty
    res = n.isEmpty();
    System.out.println("" + res);
}

}

`

Syntax of ArrayList isEmpty() Method

public boolean isEmpty()

**Return Type: It returns a boolean value, true if the list is empty, otherwise false.

**Example 2: Here, we use the **isEmpty() method **to check if an ArrayList of **strings **is empty.

Java `

// Java program to demonstrate the use of // isEmpty() method with ArrayList of Strings import java.util.ArrayList;

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

    // Creating an ArrayList of Strings
    ArrayList<String> s = new ArrayList<>();

    // Checking if the ArrayList is empty
    System.out.println("" + s.isEmpty());

    // Adding an element to 
    // the ArrayList
    s.add("Cherry");

    // Checking again if the 
    // ArrayList is empty
    System.out.println("" + s.isEmpty());
}

}

`

**Example 3: Here, we will use the **isEmpty() method **to check if an ArrayList of Objects is empty.

Java `

// Java program to demonstrate the use of // isEmpty() method with custom Objects import java.util.ArrayList;

class Person { String n; int a;

// Constructor
public Person(String n, int a) {
    this.n = n;
    this.a = a;
}

}

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

    // create an ArrayList of Person objects
    ArrayList<Person> p = new ArrayList<>();

    // check if the ArrayList is empty
    System.out.println("" + p.isEmpty());

    // add a Person object to the ArrayList
    p.add(new Person("Sweta", 24));

    // check again if the ArrayList is empty
    System.out.println("" + p.isEmpty());
}

}

`