Question

I’m terrible with regex, but I’ve had a try and a Google (and even looked in reddit’s source) and I’m still stuck so here goes:

My aim is to match the following ‘codes’ and replace them with the HTML tags. It’s just the regex I’m stuck with.

**bold text** _italic text_ ~hyperlink~ 

Here’s my attempts at the bold one:

^\*\*([.^\*]+)\*\*$ 

Why this isn’t working? I’m using the preg syntax.

Answer 1

use:

\*\*(.[^*]*)\*\* 

explanation:

\*\*      // match two *'s (.        // match any character [^*]      // that is not a * *)        // continuation of any character \*\*      // match two *'s 

in a character class ‘[ ]’ ‘^’ is only significant if it’s the first character. so (.*) matches anything, (.[^*]*) is match anything until literal *

edit: in response to comments to match asterisk within (ie **bold *text**), you’d have to use a non greedy match:

\*\*(.*?)\*\* 

character classes are more efficient non greedy matches, but it’s not possible to group within a character class (see ‘Parentheses and Backreferences…’)