java.util.TreeMap.comparator() Method

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Description

The comparator() method is used to return the comparator used to order the keys in this map, or null if this map uses the natural ordering of its keys.

Declaration

Following is the declaration for java.util.TreeMap.comparator() method.

public Comparator<? super K> comparator()

Parameters

NA

Return Value

The method call returns the comparator used to order the keys in this map, or null if this map uses the natural ordering of its keys.

Exception

NA

Example

The following example shows the usage of java.util.TreeMap.comparator() method.

package com.tutorialspoint;

import java.util.*;

public class TreeMapDemo {
   public static void main(String[] args) {
      
      // creating tree map 
      NavigableMap<Integer, String> treemap = new TreeMap<Integer, String>();

      // populating tree map
      treemap.put(2, "two");
      treemap.put(1, "one");
      treemap.put(3, "three");
      treemap.put(6, "six");
      treemap.put(5, "five");

      // using comparator
      Comparator comp = treemap.comparator();

      System.out.println("Following natural ordering");
      System.out.println("Comparator value: "+ comp);     
   }    
}

Let us compile and run the above program, this will produce the following result.

Following natural ordering
Comparator value: null