Top "Undefined" questions

Can I set variables to undefined or pass undefined as an argument?

I’m a bit confused about JavaScript’s undefined and null values. What does if (!testvar) actually do? Does it …

javascript undefined

How to resolve TypeError: Cannot convert undefined or null to object

I've written a couple of functions that effectively replicate JSON.stringify(), converting a range of values into stringified versions. When …

javascript null undefined

Undefined index error PHP

I'm new in PHP and I'm getting this error: Notice: Undefined index: productid in /var/www/test/modifyform.php on …

php forms post undefined

How can I check whether a variable is defined in JavaScript?

Which method of checking if a variable has been initialized is better/correct? (Assuming the variable could hold anything (string, …

javascript dom undefined

Undefined or null for AngularJS

When I write watch handling functions I check newVal param on undefined and null. Why does AngularJS have such a …

angularjs null undefined

How to check if a JavaScript variable is NOT undefined?

Things I’ve tried that don’t seem to work: if(lastName != "undefined") if(lastName != undefined) if(undefined != lastName)

javascript undefined

javascript set a variable if undefined

I know that I can test for a javascript variable and then define it if it is undefined, but is …

javascript undefined

Undefined Symbols for architecture x86_64: Compiling problems

So I am trying to start an assignment, my professor gives us a Main.cpp, Main.h, Scanner.cpp, Scanner.…

c++ hyperlink compilation undefined symbols

Raw_Input() Is Not Defined

I'm a seventh grade programmer so I may be missing a lot of things in this program, but for my …

python undefined raw-input

PHP How to fix Notice: Undefined variable:

code: Function ShowDataPatient($idURL) { $query =" select * from cmu_list_insurance,cmu_home,cmu_patient where cmu_home.home_id = (select …

php undefined notice