Question

Trying to form a regular expression to match the pattern of keywords, the pattern I found is like

• remove all words before : till a space occurs and all words after : till ) occurs.

find the term in this jsfiddle.

var newInput="keyword2:(content2) app keyword1:(content1) sos keyword:(content) das sad";

Im looking for an output like

app,sos,das,sad 

Answer 1

newInput.replace(/[^:\s]+:\([^)]*\)\s*/g, '');  // "app sos das sad"

Explanation

[^:\s]+:   # any character (except ' ' and ':') in front of ':'  "keyword1:'"
\([^)]*\)  # any character enclosed in '(' ')'                   "(content2)"
\s*        # trailing spaces                                     " "

This returns a space-separated string. You would have to trim it and split at spaces (or replace them) yourself.