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Date: Fri, 13 Apr 2012 16:22:14 +0200
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Subject: Re: [PHP-DEV] Allow non-variable arguments to empty()
From: paul.konyves@gmail.com (Pal Konyves)

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Well, if you want to use empty in the above mentioned situations, you might
need the change. I personally don't like using empty(). I use it only on
arrays, that's because semantically fits: array is empty.

In other situations I prefer comparing against the according return type
because it improves code readability. Dynamic typing in PHP one of the
reasons of messy code anyways.

I'm gonna try to give you alternatives of design for your examples below:

> Browsing around Google it seems that one of the most common source of
> the function call in write context error is people trying to do
> if(empty(trim($xyz)). You don't necessarily need the result of
> trim($xyz), so it's reasonable not to save it into a temporary
> variable.

if( trim($xyz) === ""); // as I talked about semantics and types above

>
> Another example for example would be a function like this:
>
> public function isValid() {
>    if (...) { $this->addError('xyz'); }
>    if (...) { $this->addError('abc'); }
>    if (...) { $this->addError('foo'); }
>    if (...) { $this->addError('bar'); }
>
>    return empty($this->getErrors());

return $this->getErrorsCount();

> }
>
> Furthermore you don't necessarily have to throw the return value away.
> For example I commonly write code like this:
>
> if (null === $result = $this->foo()) {
>    throw new Exception(...);
> }
> $result->doSomething();

I used to use this kind of formula, but I realised It neither improves
performance nor readability, especially if you want to use $result after
the if statement.

>
> You can do something similar with empty():
>
> if (empty($values = $this->getValues()) {
>    return;
> }
> $this->doSomethingWith($values);

I haven't try this but I assume this code is valid by precedence order. I
might be wrong, but still my above argument exist.

>
> I know, not everyone likes that kind of coding style, but I think it
> has it's uses.


Etienne Kneuss:
" People typically assume empty checks for the empty
string here, and it doesn't." -- why not?


Pal

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