用于空白的PHP正则表达式

Question

I am building a OOPHP web application, I am working on a regular expression that ONLY accepts lower/capital case letter along with white spaces. I have been trying to implement the white spaces but for some reason it not working, normally in JAVACC I do something like this:

(["a" - "z"])+ | (["A" - "Z"])+ | " " | "\t" | "
" | "" 

How can I rewrite the top expression in PHP? This is what I have so far (it works, but I don't know how to implement the white spaces in php).

/^[a-zA-Z]*$/

Answer 1

You can add to your character class to allow for whitespace. You can either add a space character " " if spaces are all you want to match, or use \s which matches whitespace ( , , \t, \f, and " ")

/^[a-zA-Z\s]*$/

Regular expression:

^               # the beginning of the string
[a-zA-Z\s]*     # any character of: 'a' to 'z', 'A' to 'Z',
                # whitespace (
, , \t, \f, and " ") (0 or more times)
$               # before an optional 
, and the end of the string