Variables occasionally empty how to prevent Undefined variable error?
2005
"Notice: Undefined variable", "Notice: Undefined index", and "Notice: Undefined offset" using PHP
89549
Can anyone explain this 'variable does not exist error'?
619
Why are these constructs using pre and post-increment undefined behavior?
91340
Testing if a variable is empty in a shell script
128709
Why is there a `null` value in JavaScript?
82724
How do I get perl -c to throw Undefined or Undeclared function errors?
142624
Code with undefined behavior in C#
17040
Check if an array is empty or exists
27136
Reference: What is variable scope, which variables are accessible from where and what are "undefined variable" errors?
98908
Is it good practice to set variables to null when they are no longer needed?
84590
Why do I get a "variable might not have been initialized" compiler error in my switch block?
91295
Why does a Try/Catch block create new variable scope?
112460
Can Syntax Errors be handled?
99292
Why aren't variables declared in "try" in scope in "catch" or "finally"?
114378
How to check if the string is empty?
50915
Undefined variable problem with PHP function
40229
How do I check if a variable exists?