Comparable Interface

Comparable Interface

It is available in java.lang package. This interface contains only one method compareTo().

public int compareTo(Object obj)




 –ve if obj1 has to come before obj2.
 +ve if obj1 has to come after obj2.
 0 if obj1 and obj2 are equal(Duplicate Objects).
package com.ashok.collections;

 * @author ashok.mariyala
public class MyComparable {
   public static void main(String[] args) {
      System.out.println("A".compareTo("Z"));// -25
      System.out.println("Z".compareTo("K"));// 15
      System.out.println("A".compareTo("A"));// 0


  • While Inserting the objects into the TreeSet JVM internally uses compareTo() method if we are depending on natural sorting order.
  • Sometimes we have to define our own customized sorting order, then we should go for comparator Interface.
Comparable Interface

Scroll to top