PHP trim problem - php

Question

I asked earlier how can I get rid of extra hyphens and whitespace added at the end and beginning of user submitted text for example, -ruby-on-rails- should be ruby-on-rails you guys suggested trim() which worked fine by itself but when I added it to my code it did not work at all it actually did some funky things to my code.
I tried placing the trim() code every where in my code but nothing worked can someone help me to get rid of extra hyphens and whitespace added at the end and beginning of user submitted text?
Here is my PHP code.
$tags = preg_split('/,/', strip_tags($_POST['tag']), -1, PREG_SPLIT_NO_EMPTY);
$tags = str_replace(' ', '-', $tags);

Answer 1

Update the trim statement to the following in order to update each item in the array:
foreach($tags as $key=>$value) {
$tags[$key] = trim($value, '-');
}
That should allow you to trim each value based on a string being expected.

Answer 2

If you have a string you can do this to strip hyphens from the beginning and end:
$tag = trim($tag, '-');
Your problem is that preg_split returns an array, but trim takes a string. You need to do the above for every string in the array.
Regarding trimming whitespace: if you are first converting all whitespace to hyphens then it should not be necessary to trim whitespace afterwards - the whitespace will already be gone. But be careful because the terms "whitespace" and "space" have different meanings. Your question seems to muddle these two terms.

Answer 3

Verify that the hyphen character you're attempting to trim is the same hyphen character that is wrapping -ruby-on-rails-. For example, these are all different characters that look similar: -, –, —, ―.

Answer 4

Im new to StackOverflow.com so I hope the function I wrote helps you in some way. You can specify what characters you want it to trim in the second parameter, for your example I've set it to just remove whitespace and 'dashes' by default, i've tested it using 'ruby-on-rails' and a somewhat extreme example of '- -- - - ruby-on-rails - -- - - -' and both produce the result: 'ruby-on-rails'.
The regular expression might be a bit of a q&d way of going about it but I hope it helps you, just reply if you have any problems implementing it or w/e.
function customTrim($s,$c='- ')
{
preg_match('#'.($a='[^'.$c.']').'.{1,}'.$a.'#',$s,$match);
return $match[0];
}