What do the question marks like ?: and ?! mean in Javascript regexp?
12963
What is a non-capturing group in regular expressions?
135065
&& (AND) and || (OR) in IF statements
99474
What is an exclamation point in JavaScript?
48170
What is the purpose of a question mark after a type (for example: int? myVariable)?
66172
What's the difference between  and ,  and ?
47446
Differences between Javascript regexp literal and constructor
61451
Interesting test of Javascript RegExp
99447
What is the difference between String? and String! (two ways of creating an optional variable)?
104032
Strange JavaScript idiom - what does "/xyz/.test(function(){xyz;})" do?
38716
Is there a difference between “?!” and “!?”?
15469
Difference between ! vs !! vs * in /etc/shadow
23269
What is the ?: operator
46150
Can't use exclamation mark (!) in bash?
131658
What is ?: in PHP 5.3?
29914
What is the difference between  and ?
37188
Difference between '.' , '?' and '*' in regular expressions?
120728
Question mark or period?