ReferenceError: variable is not defined - local variable within loop

[Quan_Nguyen]

Hello, so I currently have a code snippet that looks like this inside start routine (There is also a textbox that just waits for 5 seconds):

finalNumber = 1
for i in [0,1,2,3]:
    testCase = 32
    finalNumber = finalNumber + i

This works completely fine locally, but online it throws an error. Do I have to go into the javascript side and set the scope for testCase?

[wakecarter]

Hi. This should help.

Wakefield's Daily Tips

ReferenceError: varName is not defined This is one of the most common errors in online experiments [image] It is also one of the easiest to solve. The issue is one of “scope”. To define a variable so it has scope across your whole experiment, all you have to do is assign it a value. Don’t edit your JavaScript to add “var” or “let” commands. To give your variable scope assign the value in a Begin Experiment code component tab outside any clauses (i.e. no Python indents). [image] I usually s…

[Quan_Nguyen]

Ah I see, so I assume it is just good practice to make everything global then. Is it just a case of be careful with variable naming instead of using scopes?

Also thanks for the link, I haven’t seen that one before.

[wakecarter]

I think that the issue is that most PsychoPy variables in Python have global scope and JavaScript don’t use variable scope in the same way.