问题
I am trying to matching and characters from html. There are three types of ands:
and, &, &
I'm using the following code:
(&|&|\band\b)
The problem with above code is: it also matches words which start with &
i.e. © €
I've also tried the following, but it does not match & character from the start and end of line in the text.
(\s&\s|&|\band\b)
回答1:
How about
(&)|&(?!\w)|\band\b
Matches and, &, &
Does not match © €
The middle one matches an ampersand that is not followed by a word character ([A-Za-z0-9_])
回答2:
(&|&|\band\b)
is a good start. Go on by reducing the result set, you will have to specify details when not to match. There is no magic delimiter that tells a regex what you want. So the question is: how can you tell the '&' you want to accept from those you do not want to accept ?
Maybe you want to accept all '&' if not starting a word ? So:
(&[^a-zA-Z]|&|\band\b)
回答3:
Try this regex :
$regex = '/\b((\&(amp;)?)|(and))\b/i';
来源：https://stackoverflow.com/questions/11768004/php-regex-matching-ands-and-amp