ArrayList size() Method in Java

Published by user on

ArrayList size() method returns the number of elements in this list.
Syntax:

public int size()

Returns – number of elements in the ArrayList.

ArrayList Size Example

The below program shows how to use the size() method to check the number of elements in the list.

import java.util.ArrayList;

public class ArrayListSizeExample {
	public static void main(String[] args) {
		ArrayList<Integer> numbers = new ArrayList<>();
		numbers.add(11);
		numbers.add(17);
		numbers.add(32);
		numbers.add(25);
		numbers.add(80);

		System.out.println("ArrayList element : " + numbers);
		System.out.println("Number of elements in the arraylist : " + numbers.size());
	}
}

Output:

ArrayList element : [11, 17, 32, 25, 80]
Number of elements in the arraylist : 5

Size Example with User-Defined Object

Here Employee objects are added to ArrayList.

class Employee {
	private int employeeId;
	private String employeeName;

	public Employee() {
	}

	public Employee(int employeeId, String employeeName) {
		super();
		this.employeeId = employeeId;
		this.employeeName = employeeName;
	}

	@Override
	public String toString() {
		return "Employee [employeeId=" + employeeId + ", employeeName=" + employeeName + "]";
	}
}
import java.util.ArrayList;

public class ArrayListSizeDemo {

	public static void main(String[] args) {
		ArrayList<Employee> employees = new ArrayList<>();
		employees.add(new Employee(101, "Ricky"));
		employees.add(new Employee(102, "Adam"));
		employees.add(new Employee(103, "Jhon"));
		employees.add(new Employee(104, "Chris"));

		System.out.println("ArrayList elements: ");
		for (Employee employee : employees) {
			System.out.println(employee);
		}
		System.out.println("Number of elements in the arraylist: " + employees.size());

	}
}

Output:

ArrayList elements: 
Employee [employeeId=101, employeeName=Ricky]
Employee [employeeId=102, employeeName=Adam]
Employee [employeeId=103, employeeName=Jhon]
Employee [employeeId=104, employeeName=Chris]
Number of elements in the arraylist: 4

That’s all about the size() method of ArrayList in Java. Please share this article if you like it.

Further References:

ArrayList Documentation.

Categories: Java