What does equals(Object obj) do?

Question

I´ve often found an equals method in different places. What does it actually do? Is it important that we have to have this in every class?

   public boolean          


        

Answer 1

One more thing, maps use the equals method to decide if an Object is present as a key. https://docs.oracle.com/javase/8/docs/api/java/util/Map.html