Testing for variables existence not working as expected in JavaScript
5377
Is there a standard function to check for null, undefined, or blank variables in JavaScript?
57188
Using the variable "name" doesn't work with a JS object
37438
How do I use the CoffeeScript existential operator to check some object properties for undefined?
102063
Global JavaScript Variable Scope: Why doesn't this work?
26433
How does variable assignment work in JavaScript?
187
How do I check if an array includes a value in JavaScript?
56369
Global variable won't work in searching in one function
155520
Why does $('#id') return true if id doesn't exist?
83782
How to check a not-defined variable in JavaScript
44112
"Variable" variables in Javascript?
91295
Why does a Try/Catch block create new variable scope?
91340
Testing if a variable is empty in a shell script
99292
Why aren't variables declared in "try" in scope in "catch" or "finally"?
8442
Why does testfor sometimes output an error?
16905
How to use a variable for a key in a JavaScript object literal?
37735
How can I check for "undefined" in JavaScript?
4051
Boolean variable returns as string from javascript function