ArrayList size() Method in Java with Examples

Last Updated : 11 Jul, 2025

In Java, the size() method is used to get the number of elements in an ArrayList.

Example 1: Here, we will use the size() method to get the number of elements in an ArrayList of integers.

Java

// Java program to demonstrate the use of  // size() method for Integer ArrayList import java.util.ArrayList; public class GFG {  public static void main(String[] args) {    // Creating an ArrayList of Integers  ArrayList<Integer> n = new ArrayList<>();  // Adding elements to the ArrayList  n.add(21);  n.add(22);  n.add(23);  // Getting and printing the   // size of the ArrayList  int s = n.size();  System.out.println("" + s);  } }

Output

Syntax of ArrayList `size()` Method

public int size()

Returns Value: This method returns the number of elements in the list.

Example 2: Here, we use the size() method to get the number of elements in an ArrayList of strings.

Java

// Java program to demonstrate the use of  // size() method for String ArrayList import java.util.ArrayList; public class GFG {  public static void main(String[] args) {    // Creating an ArrayList of Strings  ArrayList<String> f = new ArrayList<>();  // Adding elements to the ArrayList  f.add("Apple");  f.add("Banana");  f.add("Orange");  // Getting and printing the   // size of the ArrayList  int s = f.size();  System.out.println("" + s);  } }

Output

Example 3: Here, we demonstrate how to use the size() method on an ArrayList that stores objects.

Java

// Java program to demonstrate the use of  // size() method for Object ArrayList import java.util.ArrayList; class Person {  String n;  int a;  Person(String n, int a) {  this.n = n;  this.a = a;  } } public class Main {  public static void main(String[] args) {    // Creating an ArrayList of Person objects  ArrayList<Person> p = new ArrayList<>();  // Adding elements (objects) to the ArrayList  p.add(new Person("Ram", 22));  p.add(new Person("Shyam", 25));  // Getting and printing the   // size of the ArrayList  int s = p.size();  System.out.println("" + s);  } }