Unknown error PHP regular unknown modifier errors resolution method

The following regular:

$a = ' 2 tóng dòng Canton 3 '; echo preg_replace ('/[^<]*? /', ', $a);

Will prompt:

Warning:preg_replace (): Unknown modifier ' P ' in E:\phpLearn\test.php on line 12

The reasons are:

In regular mode, the delimiter is used/done, but the regular also contains/, so this error occurs, PHP mistakenly when the trailing slash is the end of the delimiter.

Workaround:

1. Add an escape character:

echo preg_replace ('/[^<]*?<\/span>/', ' ', $a);

2. Change other delimiters:

Echo preg_replace (' {[^<]*} ', ', $a);

The above describes the unknown error PHP regular unknown modifier errors, including the unknown error content, I hope the PHP tutorial interested in a friend helpful.

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