Using regex pattern variable with preg_match

Question

I tried suggested solutions from other regex questions with preg_match but to no avail.

$match = '/^(.|a|an|and|the|this|at|in|or|of|is|for|to|its|as|by)\$/';
$filteredArray = array_filter($wordArray, function($x){
return !preg_match($match,$x);
});

It works when I include the string literal but I'd like to use a variable so I can add more words. This version works:

$filteredArray = array_filter($wordArray, function($x){
return !preg_match("/^(.|a|an|and|the|this|at|in|or|of|is|for|to|its|as|by)$/",$x);
});

I appreciate any help!

Not sure if the solution but try to use double quoutes as in working example. — Kristian
– Kristian, Commented Dec 28, 2011 at 21:03
Ups, just got it. Its because of variable scope. Posting as answer — Kristian
– Kristian, Commented Dec 28, 2011 at 21:04

outis · Accepted Answer · 2012-06-06 21:15:03Z

2

This doesnt work beause of the variable scope. You can't access variable $match from that function.

Solution in to use globals. They are accessible from everywhere.

$GLOBALS['word_regex'] = '/^(.|a|an|and|the|this|at|in|or|of|is|for|to|its|as|by)\$/';
$filteredArray = array_filter($wordArray, function($x){
return !preg_match($GLOBALS['word_regex'],$x);
});

That should work

edited Jun 6, 2012 at 21:15

outis

77.7k23 gold badges155 silver badges228 bronze badges

answered Dec 28, 2011 at 21:08

Kristian

3,5113 gold badges31 silver badges53 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Duplexia Over a year ago

Thank you very much Kristian. Sorry to be a pain, but Amadan pointed out a much better option for adding new words which would be to use in_array. I tried this but haven't gotten it to work. Could you please point out what I'm doing wrong here: $forbiddenWordsArray = array("a","an","the","this","at","in","or","of","is","for","to","its","as","by"); $filteredArray = array_filter($wordArray, function($x){ return !in_array($x,$forbiddenWordsArray); });

Duplexia Over a year ago

NVM! It was the same variable scope problem.

Kristian Over a year ago

Replace all instances of $forbiddenWordsArray with $GLOBALS['$forbiddenWordsArray'] and you should be done :) And you would be pain in the ass, then ei wouldn't be in here:) NP

outis Over a year ago

Globals are unnecessary; use a closure. Add a use ($match) to the anonymous function to access the variable (though the variable holding the pattern should be renamed; $match is usually used for the result of group capturing).

Amadan · Accepted Answer · 2011-12-28 21:02:53Z

2

Why regexp? Why not !in_array($x, $forbiddenWordsArray)? This way, easier to dynamically manage elements.

answered Dec 28, 2011 at 21:02

Amadan

200k23 gold badges253 silver badges321 bronze badges

Comments

outis · Accepted Answer · 2011-12-28 21:48:18Z

2

Anonymous functions don't automatically capture variables from the enclosing scope. You'll need to explicitly do this using a use declaration:

$shortWords = '/^(.|a|an|and|the|this|at|in|or|of|is|for|to|its|as|by)\$/';
$filteredArray = array_filter($wordArray, 
                              function($x) use ($shortWords) {
                                  return !preg_match($shortWords,$x);
                              });

answered Dec 28, 2011 at 21:48

outis

77.7k23 gold badges155 silver badges228 bronze badges

Collectives™ on Stack Overflow

Using regex pattern variable with preg_match

3 Answers 3

4 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

4 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related