用于删除开始和结束引用之间的空格的正则表达式（PHP）

Question

I would like to remove spaces if they are shown on start or end of a name inside qotes. Let me explain more on example:

This is the result i have:
" HAIRDRESSER PERSON 1" Person one businesses
" HAIR STUDIO " Person two S.P.
" HAIRDRESSER PERSON 3     " - PERSON 3 S.P.

And this is what i'm trying to achieve:
"HAIRDRESSER PERSON 1" Person one businesses
"HAIR STUDIO" Person two S.P.
"HAIRDRESSER PERSON 3" - PERSON 3 S.P.

This is the code i'm working on:

$data[$num]['title'] = preg_replace(????????, "",$row->find('td',1)->plaintext);

If you have any better solution then preg_replace i'm open for it. Thank you guys in advance.

Answer 1

It isn't safe to only search quoted text that need to be trimmed (for example: "abcd" efgh " ijkl " can be problematic with this approach and a naive pattern).

A possible way consists to search all quoted parts and to trim them using preg_replace_callback:

$data[$num]['title'] = preg_replace_callback('~"([^"]*)"~', function ($m) {
    return '"' . trim($m[1]) . '"'; }, $row->find('td', 1)->plaintext);

The advantage of this way is that the pattern used is very simple.

You can also avoid preg_replace_callback but you need a more complicated pattern:

$data[$num]['title'] = preg_replace('~"\s*+([^\s"]*(?:\s+[^\s"]+)*+)\s*"~', '"$1"', $row->find('td', 1)->plaintext);

Note that these two patterns assume that quotes are balanced and that quoted parts don't contain escaped quotes.