why javascript `var undefined` is OK but `var null` throw error
60918
Reserved keywords in JavaScript
38133
JavaScript variables declare outside or inside loop?
9266
Why does Chrome debugger think closed local variable is undefined?
151220
Why use `javascript:void(0)` instead of `javascript:` as an href do nothing placeholder?
63663
Passing window and undefined to an immediately invoked anonymous function. Why?
97010
Is there an equivalent for var_dump (PHP) in Javascript?
143636
href="javascript:" vs. href="javascript:void(0)"
19638
What is the purpose of the var keyword and when should I use it (or omit it)?
138823
Why cast null to Object?
14660
Undefined variable as function argument javascript
132398
What is null in Java?
5377
Is there a standard function to check for null, undefined, or blank variables in JavaScript?
53203
Checking for undefined
132062
Reference undefined
52008
Javascript: Do I need to put this.var for every variable in an object?
151469
What is the difference between null and System.DBNull.Value?
99292
Why aren't variables declared in "try" in scope in "catch" or "finally"?