The Java.util.Set.contains() method is used to check whether a specific element is present in the Set or not. So basically it is used to check if a Set contains any particular element.
Syntax:
boolean contains(Object element)
Parameters: The parameter element is of the type of Set. This is the element that needs to be tested if it is present in the set or not.
Return Value: The method returns true if the element is present in the set else return False.
Below program illustrate the Java.util.Set.contains() method:
// Java code to illustrate Set.contains() methodimport java.io.*;import java.util.*; public class HashSetDemo { public static void main(String args[]) { // Creating an empty Set Set<String> set = new HashSet<String>(); // Using add() method to add elements into the Set set.add("Welcome"); set.add("To"); set.add("Geeks"); set.add("4"); set.add("Geeks"); // Displaying the Set System.out.println("Set: " + set); // Check for "Geeks" in the set System.out.println("Does the Set contains 'Geeks'? " + set.contains("Geeks")); // Check for "4" in the set System.out.println("Does the Set contains '4'? " + set.contains("4")); // Check if the Set contains "No" System.out.println("Does the Set contains 'No'? " + set.contains("No")); }} |
Output:
Set: [4, Geeks, Welcome, To] Does the Set contains 'Geeks'? true Does the Set contains '4'? true Does the Set contains 'No'? false
Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Set.html#contains(java.lang.Object)
