问题
This may sound like a stupid question, but: which is faster when using it to extract keywords in a search query in php:
$keyword = preg_split('/[\s]+/', $_GET['search']);
or
$keyword = explode(' ', $_GET['search']);
回答1:
Explode is faster, per PHP.net
Tip If you don't need the power of regular expressions, you can choose faster (albeit simpler) alternatives like explode() or str_split().
回答2:
In a simple usage explode() is than faster, see: micro-optimization.com/explode-vs-preg_split (link from web.archive.org)
But preg_split has the advantage of supporting tabs (\t) and spaces with \s.
the \s metacharacter is used to find a whitespace character.
A whitespace character can be (http://php.net/manual/en/regexp.reference.escape.php):
- space character (32 =
0x20) - tab character (9 =
0x09) - carriage return character (13 =
0x0D) - new line character (10 =
0x0A) - form feed character (12 =
0x0C)
In this case you should see the cost and benefit.
A tip, use array_filter for "delete" empty items in array:
Example:
$keyword = explode(' ', $_GET['search']); //or preg_split
print_r($keyword);
$keyword = array_filter($arr, 'empty');
print_r($keyword);
Note: RegExp Perfomance
回答3:
General rule: if you can do something without regular expressions, do it without them!
if you want to split string by spaces, explode is way faster.
来源：https://stackoverflow.com/questions/27303235/in-php-which-is-faster-preg-split-or-explode