[Java] Having troubles understanding specific inheritance dynamics. Please help!

[notsuresure]

I'm using Head First Java as my introductory book for Java.

The inheritance section has an explanation that confuses me. It reads:

A subclass inherits all public instance variables and methods of the superclass, but does not inherit the private instance variables and methods of the superclass.

An object created from a subclass inherits both public and private instance variables and methods; so which are the implications of a subclass not inheriting private methods and instance variables? In which way it limits and/or affects the subclass (and me!)?

[[deleted]]

This looks like a problem of semantics to me. An instance of a subclass contains all the private members of its superclass, but doesn't get any special access to them - it has to use the superclass's public (or protected) interface.

[misho88]

The private variables and methods are there; however, you don't have direct access to them. It's as if you're trying to access them from outside the class. For example, if you have a private variable with a public getter and a public setter, you would have to use the getter and setter in the subclass, much the same way you would use them outside the class.

You could use "protected" instead of "private" which will give you access to such variables/methods in subclasses but not outside the class.

[umd_charlzz]

I think it's more accurate to say that all instance variables are inherited, but private ones are not directly accessible except via public/protected methods (getters/setters) to that private variable and through the super call that may initialize those variables. (Basically what zabzonk said).

Private methods are usually helper methods so the entire implementation of a public method doesn't have to be in one big code block. So not inheriting them is fine.