ifelse (===) vs switch/case, faster?

4rxsid

Hi all,

I need to run a check within a for loop (which could be up to 30,000 iterations ($count)). Which would be faster & why?

for ($x=0;$x<$count;$x++) {
  if ($item === "$a") {

  } elseif ($item === "$b") {

  } elseif ($item === "$c") {

  }  17 more time (20 total)
}

for ($x=0;$x<$count;$x++) {
  switch($item) {
     case '$a'; break;
     case '$b'; break;
     case '$c'; break;
     17 more as above
  }
}

between if/elseif's and case/breaks i would do "something."

....wondering if anyone would know offhand if one or the other would be faster, or has done some benchmarking regarding this type of question.

Thanks!

leatherback

Hi,

Just from looking at it, I would say off hand that the second option (Cases) is faster, since you need to make 3 if/then comparisons to get the final result if not a, b, c where-as, if I am correct, the cases are a 1 time comparison. But please.. Correct me if I am wrong..

Weedpacket

leatherback's suggestion sounds about right; I'd prefer cases over lots of elseifs in this case, if only because the resulting code would be easier to read and maintain (something that is generally more important than saving a few milliseconds). It may be the sort of thing that needs testing, though: your results may vary.

Incidentally, your switch statement appears a bit buggy: '$a' isn't the same thing as "$a".