The isEmpty()
method of java.util.ArrayList
class is used to check whether the list is empty or not. This method returns a boolean value. It returns true
if the list is empty, and false
if the list contains any elements.
Syntax
public boolean isEmpty()
Example
import java.util.ArrayList; public class ArrayListExample { public static void main(String[] args) { // Create an empty ArrayList ArrayList<String> list = new ArrayList<>(); // Check if the list is empty or not using isEmpty() boolean isEmptyInitially = list.isEmpty(); System.out.println("Is the list empty initially? " + isEmptyInitially); // Add an element to the list list.add("Hello"); // Check if the list is empty after adding an element boolean isEmptyAfterAdd = list.isEmpty(); System.out.println("Is the list empty after adding an element? " + isEmptyAfterAdd); // Clear the list (Removing all elements) list.clear(); // Check if the list is empty after clearing boolean isEmptyAfterClear = list.isEmpty(); System.out.println("Is the list empty after clearing? " + isEmptyAfterClear); } }
Output:
Is the list empty initially? true
Is the list empty after adding an element? false
Is the list empty after clearing? true
Explanation
- Initialization: An
ArrayList
is created. - Initial Check: We check whether the list is empty using
isEmpty()
method, since the list is not yet initialized, it returns true. - Adding Element: We then add an element
"Hello"
to the list. - Check After Adding: We again check the list using
isEmpty()
method, this time it returns false as the list contains an element. - Clearing the List: We delete all the elements of the list using
clear()
method. - Check After Clearing: We again check the list, this time it returns true as the list is empty.
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