Why would I use !! in JavaScript?
3574
What is the !! (not not) operator in JavaScript?
13826
In Bash scripting, what's the meaning of " $! "?
106258
What is the reason that an empty string evaluates to false in Javascript
32293
What's the difference between if(!$variable) and if(isset($variable))?
127005
' ... != null' or 'null != ....' best performance?
101523
Why is using `<<-` frowned upon and how can I avoid it?
101128
What is "?:" notation in JavaScript?
154567
difference between null != something and something != null
50416
What does the >?= operator mean?
146525
Javascript - breaking up string literals... why?
47477
What is "!!" in C?
79050
Python ( or general programming ). Why use  instead of != and are there risks?
50931
What is the difference between #!/bin/sh and #!/bin/bash?
16604
What's the purpose (if any) of "javascript:" in event handler tags?
115437
Javascript || operator
118838
What does !function ($) { $(function(){ }) }(window.jQuery) do?
64289
How does !!~ (not not tilde/bang bang tilde) alter the result of a 'contains/included' Array method call?