Match ":)" smiley followed by word boundary

Question

I am trying to match smileys followed by a word boundary \b.

Let's say I wanna match :p and :) followed by \b.

/(:p)\b/ is working fine but why is /(:\))\b/ behaving the opposite?

Answer 1

You cannot use a word boundary here as ) is a non-word character.

Simply put: \b allows you to perform a whole words only search using a regular expression in the form of \bword\b. A word character is a character that can be used to form words. All characters that are not word characters are non-word characters.

Use (:\)) to match :) and capture it in the first capturing group.

Use /(:\))(?![a-z0-9_])/i in order to avoid matching any :)s with letters after the smiley. It is an equivalent of (:\))\B.

\B is the negated version of \b. \B matches at every position where \b does not. Effectively, \B matches at any position between two word characters as well as at any position between two non-word characters.

See demo 1 and demo 2.

Answer 2

Addition to stribizhev's answer.. you can use (:\))\B

Examples for when to use what:

\b : string = That man is batman. regex = \bman\b matches only man and not the man in batman because position between tm is not a word boundary (it is a word).

\B : string = I am bat-man and he is super - man. regex = \B-\B matches - in super - man whereas \b-\b matches - in bat-man since position between t- and -m are word boundaries.. and (space) -, - (space) is not.

Note: It is easy to understand if you consider \b or \B as a position between two characters and if the transition from character to character is word to word or word to non word