Creating functions that ignore if a variable is already set
57783
What are the use cases for different scoping constructs?
66693
Closure in python?
37773
How do I detect whether a Python variable is a function?
136646
Update a function avoiding infinite recursion
83608
Is it possible to dereference variable id's?
124612
Use counter before its value is set
83782
How to check a not-defined variable in JavaScript
13884
How to change a variable in a calling function from a called function?
74359
How would I skip optional arguments in a function call?
112764
Prevent Javascript from being executed twice
128503
Expand scope of a variable initialized in a if/else sequence
105344
How do I clear all variables with subscripts?
44858
JavaScript isset() equivalent
98127
PHP function with variable as default value for a parameter
107469
What is the best way to return an error from a function when I'm already returning a value?
5377
Is there a standard function to check for null, undefined, or blank variables in JavaScript?
137325
Is it possible to overwrite a function in PHP