如何检查是否有符号 - 在PHP中出现正则表达式？

Question

This if condition:

if (preg_match('/^[a-zA-Z_]+\z/', $network_path)) 

Skips strings like: bla-bla-bla-bla

How can I Improve this regex so it would accept strings like above.. ?

Answer 1

This [a-zA-Z_] is a character class. This construct matches one character from those defined inside the square brackets.

So this class matches a to z, A to Z and the underscore. If you want to match also a dash, you just need to add it to the class. But be careful, - is a special character inside a character class, so if you want to match it literally you need to escape it or put it to the start or the end of the class.

if (preg_match('/^[-a-zA-Z_]+\z/', $network_path))

or

if (preg_match('/^[a-zA-Z_-]+\z/', $network_path))

or

if (preg_match('/^[a-zA-Z\-_]+\z/', $network_path))