Public const variable or private with a get function, which is preferable?

Question

So I have a variable I often have to call outside the class, I was told that I should do this:

class Foo{
    public:
        //stuff
    Type getVariable();
    private:
        Type Variable;
        //stuff
}

But why can't I just use:

class Foo{
    public:
        //stuff
    const Type variable
    private:
        //stuff
}

Do you want to change the variable in any of the member functions? Then don't make it `const`. — Some programmer dude, Mar 26 '13 at 16:11

score 5 · Accepted Answer · answered Mar 26 '13 at 16:11

5

You can, but don't expect the same results.

In the second case, you can't modify variable anymore, not even inside the functions.

They're different things.

answered Mar 26 '13 at 16:11

Luchian Grigore

But in terms of "security", it comes down to the same thing? Would this be the only aspect that distinguishes these two? – Jan M. Mar 26 '13 at 16:47
@PatronBernard no, **all** aspects distinguish the two. They're completely unrelated. – Luchian Grigore Mar 26 '13 at 16:48
@PatronBernard, public vs. private is merely a compile time check. It's not really "security". I could still access the variable and modify it, given sufficient motivation. `const` possibly allows the compiler to move the storage into a read-only memory area, and attempts to modify it would cause an access violation, but this varies wildly by compiler and architecture. – Nathan Ernst Mar 26 '13 at 21:31

1 Answers1