Initialize class elements: Yes/No, which value?

[benjamin.s...@googlemail.com]

Hello everybody,

I got a tiny question for which I could not find any proper answer by
simply googling or the likes.
I am not quite sure what might be the best way to initialize my class
elements. For now I initialize them with values of the type they
actually should contain. Example:

private $_users = array();
private $_admin_name = '';
private $_max_users = 0;
private $_user_model = null;

I thought this would be a good way but I found it a general source of
some errors in my code when I want to use those elements in
comparisons. When I pass them though many methods and other classes at
some point I maybe won't remember what the type of this variable was.
And since I like to do strict comparison (===, !==) it can make my
conditions fail even they should not. And please do not encourage me
to use hungarion notation. That is really ugly to me.

So I just want to know what your general approach und initializing
class elements is and why you prefer your way over the others.

Thanks in advance
Benjamin

[Jerry Stuckle]

benjamin.s...@googlemail.com wrote:
> Hello everybody,
>
> I got a tiny question for which I could not find any proper answer by
> simply googling or the likes.
> I am not quite sure what might be the best way to initialize my class
> elements. For now I initialize them with values of the type they
> actually should contain. Example:
>
> private $_users = array();
> private $_admin_name = '';
> private $_max_users = 0;
> private $_user_model = null;
>
> I thought this would be a good way but I found it a general source of
> some errors in my code when I want to use those elements in
> comparisons. When I pass them though many methods and other classes at
> some point I maybe won't remember what the type of this variable was.
> And since I like to do strict comparison (===, !==) it can make my
> conditions fail even they should not. And please do not encourage me
> to use hungarion notation. That is really ugly to me.
>

No problem with the way you initialize them - but you should ALWAYS
remember what the type is. It's much easier if you document your class
before writing the code.

> So I just want to know what your general approach und initializing
> class elements is and why you prefer your way over the others.
>
> Thanks in advance
> Benjamin

No 100% rule, but in general:

1) Initialize array members to empty arrays,
2) Initialize elements with valid defaults to those default values
3) Initialize other elements to a value indicating it's invalid (often
times null).

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstu...@attglobal.net
==================

[Captain Paralytic]

On Jan 4, 2:38 am, "benjamin.schneider...@googlemail.com"

Well it seems to me that this has nothing whatsoever to do with
initialization.

Regardless as to whether the variables have their initial or a
subsequent value, if you want to make strict comparisons, then you
have to know what types you are dealing with.

So you have some choices:
1) Use Hungarian Notation to help you keep track of the types
2) Keep a data dictionary to hand so that you can easily look up the
type
3) Stop using strict comparisons