PHP preg_split: Split string by other strings

Question

I want to split a large string by a series of words.

E.g.

$splitby = array('these','are','the','words','to','split','by');
$text = 'This is the string which needs to be split by the above words.';

Then the results would be:

$text[0]='This is';
$text[1]='string which needs';
$text[2]='be';
$text[3]='above';
$text[4]='.';

How can I do this? Is preg_split the best way, or is there a more efficient method? I'd like it to be as fast as possible, as I'll be splitting hundreds of MB of files.

Answer 1

This should be reasonably efficient. However you may want to test with some files and report back on the performance.

$splitby = array('these','are','the','words','to','split','by');
$text = 'This is the string which needs to be split by the above words.';
$pattern = '/\s?'.implode($splitby, '\s?|\s?').'\s?/';
$result = preg_split($pattern, $text, -1, PREG_SPLIT_NO_EMPTY);

• Regular Expression Demo: http://rubular.com/r/jNUO1KvrXg
• PHP Code Demo: http://www.ideone.com/ov3Wl

Answer 2

preg_split can be used as:

$pieces = preg_split('/'.implode('\s*|\s*',$splitby).'/',$text,-1,PREG_SPLIT_NO_EMPTY);

See it