The clear() method of ArrayList in Java is used to remove all the elements from a list. The list will be empty after this call returns so whenever this operation has been performed all elements of the corresponding ArrayList will be deleted so it does it becomes an essential function for deleting elements in ArrayList from memory leading to optimization.
Syntax
public void clear()
Parameters
clear method does not need any parameters.
Return Type
It does not return any value as it removes all the elements in the list and makes it empty.
Tip: It does implement the following interfaces as follows: Serializable, Cloneable, Iterable<E>, Collection<E>, List<E>, RandomAccess
Example of ArrayList clear() Method
Example 1:
Java
// Java Program to Illustrate Working of clear() Method// of ArrayList class// Importing required classesimport java.util.ArrayList;// Main classpublic class GFG { // Main driver method public static void main(String[] args) { // Creating an empty Integer ArrayList ArrayList<Integer> arr = new ArrayList<Integer>(4); // Adding elements to above ArrayList // using add() method arr.add(1); arr.add(2); arr.add(3); arr.add(4); // Printing the elements inside current ArrayList System.out.println("The list initially: " + arr); // Clearing off elements // using clear() method arr.clear(); // Displaying ArrayList elements // after using clear() method System.out.println( "The list after using clear() method: " + arr); }} |
The list initially: [1, 2, 3, 4] The list after using clear() method: []
Example 2:
In this example, we create a new ArrayList called animals and add some elements to it using the add() method. Then, we print the elements of the ArrayList.
Next, we call the clear() method to remove all elements from the ArrayList. Finally, we print the elements of the ArrayList again to demonstrate that it is now empty.
Java
import java.util.ArrayList;public class Main { public static void main(String[] args) { // Create a new ArrayList ArrayList<String> animals = new ArrayList<>(); // Add some elements to the ArrayList animals.add("Dog"); animals.add("Cat"); animals.add("Rabbit"); animals.add("Bird"); // Print the elements of the ArrayList System.out.println("Animals: " + animals); // Clear the ArrayList using the clear() method animals.clear(); // Print the elements of the ArrayList after // clearing it System.out.println("Animals after clearing: " + animals); }} |
Animals: [Dog, Cat, Rabbit, Bird] Animals after clearing: []
