HashSet contains() Method in Java

Last Updated : 26 Nov, 2018

The Java.util.HashSet.contains() method is used to check whether a specific element is present in the HashSet or not. So basically it is used to check if a Set contains any particular element.

Syntax:

Hash_Set.contains(Object element)

Parameters: The parameter element is of the type of HashSet. 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.HashSet.contains() method:

// Java code to illustrate HashSet.contains() method 
import java.io.*; 
import java.util.HashSet; 
  
public class HashSetDemo { 
    public static void main(String args[]) 
    { 
        // Creating an empty HashSet 
        HashSet<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 HashSet 
        System.out.println("HashSet: " + 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:

HashSet: [4, Geeks, Welcome, To]
Does the Set contains 'Geeks'? true
Does the Set contains '4'? true
Does the Set contains 'No'? false

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