Set isEmpty() method in Java with Examples
The java.util.Set.isEmpty() method is used to check if a Set is empty or not. It returns True if the Set is empty otherwise it returns False.
Syntax:
boolean isEmpty()
Parameters: This method does not take any parameter
Return Value: The method returns True if the set is empty else returns False.
Below program illustrate the java.util.Set.isEmpty() method:
// Java code to illustrate isEmpty() import java.io.*; import java.util.*; public class SetDemo { public static void main(String args[]) { // Creating an empty Set Set<String> set = new HashSet<String>(); // Use add() method to add elements into the Set set.add( "Welcome" ); set.add( "To" ); set.add( "Beginner" ); set.add( "4" ); set.add( "Beginner" ); // Displaying the Set System.out.println( "Set: " + set); // Check for the empty set System.out.println( "Is the set empty? " + set.isEmpty()); // Clearing the set using clear() method set.clear(); // Again Checking for the empty set System.out.println( "Is the set empty? " + set.isEmpty()); } } |
Output:
Set: [4, Beginner, Welcome, To] Is the set empty? false Is the set empty? true
Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Set.html#isEmpty()
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