Exiting/Entering a function

[ramoneguru]

I've always been told that a function should have one exit and one entrance. Lately, I've been seeing code like this:

function foo($temp)
{
if ($temp >= 0)
return true;
else
return false;

}

Nothing really wrong with that only I've been told to do it like this:

function foo($temp)
{
$status = false;
if ($temp >= 0)
$status = true;

return $status;

}

Is there really any significant difference between the two? Any security risks?

--Nick

[eelixduppy]

>> significant difference

Not much of a difference at all. The first one, in my opinion, is much more readable and the way I would have done it. The second way, while it still does the same thing, makes it a little less obvious what it will return. Both are acceptable.

[pinterface]

I'd write that as:

  function foo($temp) {
    return $temp >= 0;
  }

, which kinda makes the question moot. ;)

Generally, advice to write code that second way comes from people taking structured programming too far. Going through awful contortions to ensure a function only has one exit point is nuts when multiple exit points make more sense.

For instance, I'd much prefer

  function bar($quux) {
    if (some_condition($quux)) return false;
    // do other stuff...
    return true;
  }

over

  function bar($quux) {
    if (some_condition($quux)) {
      $ret = false;
    } else {
      // do other stuff...
      $ret = true;
    }
    return $ret;
  }

Partially because the first is shorter, but also because it fits how I think about the problem better: "If $quux meets some condition bail out, otherwise do some actual work." versus "Uh, do some stuff, or do some other stuff, then maybe return something.".

[ramoneguru]

Yeah, I figured one was just more structure. Sounds good though, no real significant difference :-)
--Nick