Using superclass to initialise a subclass object java [duplicate]

Answer 1

The main reason to do the former is for function calls that expect the super class. If you have a class A that has a method like this

public static void insert(SuperClass b) {
    //do something
}

and you have the

SuperClass object = new SubClass();

you can do

A.insert(object);

But if you do

SubClass object new SubClass();

you can't do

A.insert(object);

unless you add a method like this to A

public static void insert(SubClass b) {
     //do something
}

This helps you cut down on redundant or copied code and keep things cleaner.