Commenting Regular Expressions

Question

I\'m trying to comment regular expressions in JavaScript.

There seems to be many resources on how to remove comments from code using regex, but not actuall

Answer 1

In several other languages (notably Perl), there's the special x flag. When set, the regexp ignores any whitespace and comments inside of it. Sadly, javascript regexps do not support the x flag.

Lacking syntax, the only way to leverage readability is convention. Mine is to add a comment before the tricky regular expression, containing it as if you've had the x flag. Example:

/*
  \+?     #optional + sign
  (\d*)   #the integeric part
  (       #begin decimal portion
     \.
     \d+  #decimal part
  )
 */
var re = /\+?(\d*)(\.\d+)/;

For more complex examples, you can see what I've done with the technique here and here.