custom function that uses isset() returning undefined variables when used
125952
PHP take string and check if that string exists as a variable
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How can I check for an empty/undefined/null string in JavaScript?
96416
AmpScript Custom Functions
106904
PHP Default Function Parameter values, how to 'pass default value' for 'not last' parameters?
34563
Why does PHP consider 0 to be equal to a string?
137386
PHP bug with converting object to arrays
134996
How can I temporarily disable the "return value might be undefined" warning?
90598
PHP considers null is equal to zero
37735
How can I check for "undefined" in JavaScript?
88588
php $_GET and undefined index
130453
Redefining PHP function?
156722
How to override built-in PHP function(s)?
123342
How to call a function from a string stored in a variable?
40229
How do I check if a variable exists?
89549
Can anyone explain this 'variable does not exist error'?
88906
Access array returned by a function in php
27729
Why and how do you use anonymous functions in PHP?