java why should equals method input parameter be Object

Question

I\'m going through a book on data structures. Currently I\'m on graphs, and the below code is for the vertex part of the graph.

class Vertex{
    /         


        

Answer 1

It is because the author is overriding equals. Equals is specified in java.lang.Object and is something that all classes inherrits from.

See the javadoc for java.lang.Object