Question

The below is my code,

public class Myclass{
     some code is here.
   }

   public static void main(String args[]){
     Set<Myclass> set = new HashSet<Myclass>();
     Myclass mc = new Myclass();
     for(int i=0;i<2;i++){
       set.add(mc);
     }
     System.out.println("size of set : "+set.size());
   }

The above code is print the output 2 but it will be 1. Is there any wrong with my code, if so then please suggest me how to avoid adding duplicate entries in set. I have override the equals() in my Myclass class.

Please reply me as soon as possible.

Thank you.

Answer 1

You presumably need to implement equals() and hashCode() for MyClass, otherwise it won’t properly check equality.