❮ Java8 Functional Interfaces Java9 Collection Factory Methods ❯

Java Example - Collection Length

The following example demonstrates how to use the Collections class's collection.add() to add data and collection.size() to calculate the length of the collection:

Main.java File

import java.util.*;

public class Main {
   public static void main(String [] args) {   
      System.out.println( "Collection Example!\n" ); 
      int size;
      HashSet collection = new HashSet();
      String str1 = "Yellow", str2 = "White", str3 = "Green", str4 = "Blue";  
      Iterator iterator;
      collection.add(str1);    
      collection.add(str2);   
      collection.add(str3);   
      collection.add(str4);
      System.out.print("Collection Data: ");  
      iterator = collection.iterator();     
      while (iterator.hasNext()){
         System.out.print(iterator.next() + " ");  
      }
      System.out.println();
      size = collection.size();
      if (collection.isEmpty()){
         System.out.println("Collection is empty");
      }
      else{
         System.out.println("Collection Length: " + size);
      }
      System.out.println();
   }
}

The output of the above code is:

Collection Example!

Collection Data: White Yellow Blue Green 
Collection Length: 4

Java Examples

❮ Java8 Functional Interfaces Java9 Collection Factory Methods ❯