Get the count of elements in HashMap in Java

Java 8Object Oriented ProgrammingProgramming

Use the size() method to get the count of elements.

Let us first create a HashMap and add elements −

HashMap hm = new HashMap();
// Put elements to the map
hm.put("Maths", new Integer(98));
hm.put("Science", new Integer(90));
hm.put("English", new Integer(97));

Now, get the size −

hm.size()

The following is an example to get the count of HashMap elements −

Example

 Live Demo

import java.util.*;
public class Demo {
   public static void main(String args[]) {
      // Create a hash map
      HashMap hm = new HashMap();
      // Put elements to the map
      hm.put("Maths", new Integer(98));
      hm.put("Science", new Integer(90));
      hm.put("English", new Integer(97));
      hm.put("Physics", new Integer(91));
      hm.put("Chemistry", new Integer(93));
      // Get a set of the entries
      Set set = hm.entrySet();
      // Get an iterator
      Iterator i = set.iterator();
      // Display elements
      while(i.hasNext()) {
         Map.Entry me = (Map.Entry)i.next();
         System.out.print(me.getKey() + ": ");
         System.out.println(me.getValue());
      }
      System.out.println();
      System.out.println("Count of elements = "+hm.size());
   }
}

Output

Maths: 98
English: 97
Chemistry: 93
Science: 90
Physics: 91
Size: 5
raja
Published on 11-Jan-2019 12:02:55
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