- Java.util Package Classes
- Java.util - Home
- Java.util - ArrayDeque
- Java.util - ArrayList
- Java.util - Arrays
- Java.util - BitSet
- Java.util - Calendar
- Java.util - Collections
- Java.util - Currency
- Java.util - Date
- Java.util - Dictionary
- Java.util - EnumMap
- Java.util - EnumSet
- Java.util - Formatter
- Java.util - GregorianCalendar
- Java.util - HashMap
- Java.util - HashSet
- Java.util - Hashtable
- Java.util - IdentityHashMap
- Java.util - LinkedHashMap
- Java.util - LinkedHashSet
- Java.util - LinkedList
- Java.util - ListResourceBundle
- Java.util - Locale
- Java.util - Observable
- Java.util - PriorityQueue
- Java.util - Properties
- Java.util - PropertyPermission
- Java.util - PropertyResourceBundle
- Java.util - Random
- Java.util - ResourceBundle
- Java.util - ResourceBundle.Control
- Java.util - Scanner
- Java.util - ServiceLoader
- Java.util - SimpleTimeZone
- Java.util - Stack
- Java.util - StringTokenizer
- Java.util - Timer
- Java.util - TimerTask
- Java.util - TimeZone
- Java.util - TreeMap
- Java.util - TreeSet
- Java.util - UUID
- Java.util - Vector
- Java.util - WeakHashMap
- Java.util Package Extras
- Java.util - Interfaces
- Java.util - Exceptions
- Java.util - Enumerations
- Java.util Useful Resources
- Java.util - Useful Resources
- Java.util - Discussion
Java HashSet size() Method
Description
The Java HashSet size() method is used to get the number of elements in this set.
Declaration
Following is the declaration for java.util.HashSet.size() method.
public int size()
Parameters
NA
Return Value
The method call returns the number of elements in this set.
Exception
NA
Getting Size of the HashSet of Integers Example
The following example shows the usage of Java HashSet size() method to print the count of entries of the HashSet. We've created a HashSet object of Integer. Then few entries are added using add() method and then set size is printed using size() method.
package com.tutorialspoint; import java.util.HashSet; public class HashSetDemo { public static void main(String args[]) { // create hash set HashSet <Integer> newset = new HashSet <>(); // populate hash set newset.add(1); newset.add(2); newset.add(3); // print the size of the set System.out.println("Hash set size: "+ newset.size()); } }
Output
Let us compile and run the above program, this will produce the following result.
Hash set size: 3
Getting Size of the HashSet of Strings Example
The following example shows the usage of Java HashSet size() method to print the count of entries of the HashSet. We've created a HashSet object of String. Then few entries are added using add() method and then set size is printed using size() method.
package com.tutorialspoint; import java.util.HashSet; public class HashSetDemo { public static void main(String args[]) { // create hash set HashSet <String> newset = new HashSet <>(); // populate hash set newset.add("Learning"); newset.add("Easy"); newset.add("Simply"); // print the size of the set System.out.println("Hash set size: "+ newset.size()); } }
Output
Let us compile and run the above program, this will produce the following result.
Hash set size: 3
Getting Size of the HashSet of Objects Example
The following example shows the usage of Java HashSet size() method to print the count of entries of the HashSet. We've created a HashSet object of Student objects. Then few entries are added using add() method and then set size is printed using size() method.
package com.tutorialspoint; import java.util.HashSet; public class HashSetDemo { public static void main(String args[]) { // create hash set HashSet <Student> newset = new HashSet <>(); // populate hash set newset.add(new Student(1, "Julie")); newset.add(new Student(2, "Robert")); newset.add(new Student(3, "Adam")); // print the size of the set System.out.println("Hash set size: "+ newset.size()); } } class Student { int rollNo; String name; Student(int rollNo, String name){ this.rollNo = rollNo; this.name = name; } @Override public String toString() { return "[ " + this.rollNo + ", " + this.name + " ]"; } }
Output
Let us compile and run the above program, this will produce the following result.
Hash set size: 3
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