Get Size of Java TreeMap Example

This Java Example shows how to get the size or nubmer of key value pairs stored in TreeMap using size method.

import java.util.TreeMap;

public class GetSizeOfTreeMapExample {

 public static void main(String[] args) {

  // create TreeMap object
  TreeMap tMap = new TreeMap();

  /**
   * To get the size of TreeMap use int size() method
   * of TreeMap class.It returns the number of key 
   * value pairs stored in TreeMap object.
   **/
  System.out.println("Size of TreeMap : " + tMap.size());

  // add key value pairs to TreeMap using put method
  tMap.put("1", "One");
  tMap.put("2", "Two");
  tMap.put("3", "Three");

  System.out.println("Size of TreeMap after addition : " + tMap.size());

  // remove one element from TreeMap using remove method
  Object obj = tMap.remove("2");

  System.out.println("Size of TreeMap after removal : " + tMap.size());
 }
}

The output is:


Size of TreeMap : 0
Size of TreeMap after addition : 3
Size of TreeMap after removal : 2