如何在正则表达式中允许使用“-”？

Question

I am trying to allow '-' in the regular expression for telephone numbers, but the - is usually used for ranges (eg AZ). So how do I allow just the character? I tried escapting using /-, but that's not working.

$reg_num = "/[^0-9+ ()]/"; 

Answer 1

You need to escape it with a backslash \\ . So it should be written as \\- .

Answer 2

Write it in the end instead of '-' being between two characters. Very simplified example: [0-9-] would match 099-2233-3333 where 0-9 is a range, and the - in the end is a seperate dash sign to match.

Answer 3

Put it first in the range, like [^-0-9+ ()] . The hyphen needs to separate two characters to define a range; if it isn't (in this case because the ^ is also interpreted as a modifier, not a character in the set), then it's just a character in the set like any other.

Answer 4

escaping using \\-

\

is escape character!