Question

Is there a reason why I should not be marking everything as public in our intranet reporting app?

No one outside out co will ever have access to this code – we have about 20 projects – mostly small and specific.

Is there really a reason why we should be marking things anything other than public?

I have my own thoughts on this which I’m trying to omit as I want this to be unbiased.

(I have sexed up the title slightly)

Answer 1

Look up Encapsulation and/or “Information Hiding”:

In object-oriented programming, information hiding (by way of nesting of types) reduces software development risk by shifting the code’s dependency on an uncertain implementation (design decision) onto a well-defined interface. Clients of the interface perform operations purely through it so if the implementation changes, the clients do not have to change.

If you mark the members of every class as public, you’re making for a maintenance nightmare where future developers (including yourself) will be unsure on which parts of the class are meant to be permanent (the contract) and which are purely implementation details.