Re: Allow non-variable arguments to empty()

On Fri, Apr 13, 2012 at 16:22, Pal Konyves <paul.konyves@gmail.com> wrote: > 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? What I meant is that when people do: $str = trim($foo); if (empty($str)) { } they typically want to check if the string is empty, i.e. contains 0 characters. They usually forget that empty() will also return true on the string "0". > > > Pal -- Etienne Kneuss http://www.colder.ch