Java HashSet contains() Method with Examples

by Online Tutorials Library July 22, 2022

Java HashSet contains() Method

The contains() method of Java HashSet class is used to check if this HashSet contains the specified element or not. It returns true if element is found otherwise, returns false.

Syntax

Following is the declaration of contains() method:

Parameter

Parameter	Description	Required/Optional
o	It is the element whose presence in this set is to be tested.	Required

Returns

The contains() method returns true if this set contains the specified element.

Exceptions

Compatibility Version

Java 1.2 and above

Example 1

  import java.util.*;    public class HashSetContainsExample1 {    public static void main(String[] args) {        //Create hash set      HashSet hset = new HashSet();            //Add elements to hash set      hset.add(11);       hset.add(21);      hset.add(15);        hset.add(110);       hset.add(151);       //Print HashSet elements      System.out.println(“Hash set Elements: “+ hset);      //Check for “110” in the set    System.out.println(“Does the Set contains ‘110’? :- “+hset.contains(110));    //Check if the Set contains “555”    System.out.println(“Does the Set contains ‘555’? :- “+hset.contains(555));    }    }    

Test it Now

Output:

Hash set Elements: [21, 151, 11, 110, 15]  Does the Set contains '110'? :- true  Does the Set contains '555'? :- false

Example 2

  import java.util.*;    public class HashSetContainsExample2 {    public static void main(String[] args) {    //Get HashMap object from method init()  @SuppressWarnings(“rawtypes”)  HashSet studentSet = init();  //Ask input from console  System.out.print(“Enter student name:”);  Scanner s = new Scanner(System.in);  String name = s.nextLine();  s.close();  //Check if the console input is in the student database  if(studentSet.contains(name)){  System.out.println(name +” found on student list.”);  }  else{  System.out.println(name +” name not on the student list.”);  }  }  @SuppressWarnings(“rawtypes”)  private static HashSet init() {  //CreateHashSet object  HashSet studentSet = new HashSet<>();  //Add values to HashMap  studentSet.add(“Rishi”);  studentSet.add(“Sharon”);  studentSet.add(“Pawan”);  return studentSet;  }    }   

Test it Now

Output:

Enter student name: Rishi  Rishi found on student list.

Example 3

  import java.util.*;  public class HashSetContainsExample3 {  public static void main(String[] args) {  //Create HashSet object  HashSet hashset = new HashSet();  //Adding elements to HashSet  hashset.add(“Facebook”);  hashset.add(“Twitter”);  hashset.add(“Instagram”);  //Print the elements of the HashSet  System.out.println(“Elements of the HashSet:”);  for(String val : hashset)  {  System.out.println(val);  }  //Check if the hashSet contains “Whatsapp”  System.out.println(“Does the HashSet contains ‘Whatsapp’? :- “+hashset.contains(“Whatsapp”));  //Check if the hashSet contains “Facebook”  System.out.println(“Does the HashSet contains ‘Facebook’? :- “+hashset.contains(“Facebook”));  }  }  

Test it Now

Output:

Elements of the HashSet:  Twitter  Instagram  Facebook  Does the HashSet contains 'Whatsapp'? :- false  Does the HashSet contains 'Facebook'? :- true

Next TopicHashSet isEmpty() Method

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Java HashSet contains() Method with Examples

Java HashSet contains() Method

Syntax

Parameter

Returns

Exceptions

Compatibility Version

Example 1

Example 2

Example 3

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