ArrayList Methods

Learn the basic ArrayList methods.

This section lists some common methods of an ArrayList class. We’ll cover them one by one in detail.

Add items

Variation I

We use the add(E e) method to add elements to the ArrayList. It takes an element, e, of E type, appends it to the end of the list, and returns true.

Press + to interact
import java.util.ArrayList;
class AddItems
{
public static void main(String args[])
{
ArrayList<String> students = new ArrayList<String>(); // empty list
// Adding elements
students.add("James");
students.add("Allen");
System.out.println(students);
}
}

Initially, we create an empty ArrayList with the name, students. Look at line 10. We call the add() method on students and send James as an argument. Likewise, we add Allen in the next line. Later, at line 13, we print the list and get the output: [James, Allen].

Variation II

We use the add(int index, E e) method to insert the specified element, e, at the specified position, index, in a list. It’s a void method.

Press + to interact
import java.util.ArrayList;
class AddItems
{
public static void main(String args[])
{
ArrayList<String> students = new ArrayList<String>(); // empty list
// Adding elements
students.add(0, "James");
students.add(1, "Allen");
System.out.println(students);
students.add(0, "Kim");
System.out.println(students);
}
}

Initially, we create an empty ArrayList with the name: students. Look at line 10. We call the add() method on students and send 00, and James as arguments. Likewise, we add Allen at the 11 ...

Get hands-on with 1400+ tech skills courses.