Should array variables always be declared as arrays?

Question

When declaring variables at the top of a class, does it matter if I do:

private $garbage_values;

instead of:

private $garbage_values = [];

Of course, there will be foreach loops within the class that reference the array, and the array may be empty. Does this matter?

not really as far as I know. PHP is pretty flexible. But you must always check if it's an array before running it through a foreach if you don't declare it initially as an array. — A. L
– A. L, Commented Dec 11, 2016 at 7:42
Ah - that's what I meant. So private $value would generate an error if I tried to run a foreach on it when empty? — daninthemix
– daninthemix, Commented Dec 11, 2016 at 7:58
yes. So either make it an empty array so you don't need to check. Or add a check before doing foreach. Anyway, you could easily test these small things in phpfiddle if you don't want to run a script. — A. L
– A. L, Commented Dec 11, 2016 at 8:35

Ikari · Accepted Answer · 2016-12-11 09:20:25Z

2

Basically, if you'd want any type of variable to work in a foreach like it should, it should fall into the iterable pseudo-type.

So if you use a variable that does not fall into the iterable pseudo-type, in a foreach an error would spring up.

And in your case, i.e. private $foo; if you leave it like that, it basically contains the value null which does not fall into iterable, so it would fail.

Whereas, if you use private $foo = []; it contains an empty array, which indeed does fall into the iterable pseudo-type and can be used flawlessly in a foreach.

answered Dec 11, 2016 at 9:20

Ikari

3,2443 gold badges31 silver badges35 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Should array variables always be declared as arrays?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related