Is there a difference between "if not x" and "if x is None"?
111657
Difference between "if x" and "if x is not None"
93772
Why is isNaN(null) == false in JS?
8309
Does Python have a ternary conditional operator?
132461
NOT IN vs NOT EXISTS
14264
What is better: multiple "if" statements or one "if" with multiple conditions?
66078
Do the following negations mean the same thing?
23730
Why is 'True == not False' a syntax error in Python?
93761
"if", and "elif" chain versus a plain "if" chain
4461
Order of "not" with infinitive
83392
Why is "if not someobj:" better than "if someobj == None:" in Python?
149035
Using "neither" without "nor"
147155
How to differentiate between if zero conditional and if first conditional?
139105
Difference between if () { } and if () : endif;
3574
What is the !! (not not) operator in JavaScript?
6935
What's the difference between "either" and "neither"?
151917
Difference between "not a", "no" and "not any"
140759
What is exactly the difference between $\forall x \neg P(x)$ and $\neg \forall xP(x)$?