Variable highlighting isn't working

I can't seem to get variables to be highlighted in the editor. If I understand correctly, this should be controlled by the checkbox in: Preferences > Colors > Programming Tools > Variables and function colors > Variables with shared scope. I've tried all combinations of checking, unchecking, changing the color, restarting Matlab between changes, etc. and nothing works. My function variables remain the same default text color (i.e. black if background is white, white if background is black).

I'm running 2019a on Windows 10.

[Rik]

So when you click on a variable, that specific variable doesn't change color? Or do you want all variables to change color?

Answer 1

[Stephen23]

"I can't seem to get variables to be highlighted in the editor."

MATLAB automatically highlights all reachable instances of a variable when you click on it:

https://blogs.mathworks.com/community/2010/10/11/automatic-variable-highlighting/

I suspect that you do not actually mean highlighting (which refers to a rectangular background of a different color to the normal background) but to changing the text color: the MATLAB IDE does not have an option to select a different text color just for variables.

"Variables with shared scope" does NOT refer to ALL variables in a function. It refers only to variables that are common across multiple workspaces, e.g. those used in a nested function and also in the main/parent function.

That option works correctly on my MATLAB version (R2015b), as I show below:

Selected:

Unselected:

You can see how the shared variable z is colored when I select that option, and not colored when the option is not selected.

[Trevor Bruns]

Ah! I didn't fully understand what that meant. Makes sense now, thanks!

Answer 2

[per isakson]

I guess the problem is with the meaning of "Variables with shared scope". See Check Variable Scope in Editor

The gui you refer to shows this sample (R2018b)

Type the text of this sample in the editor. Aren't the variables hightlighted as in this image?

[Trevor Bruns]

Yep, that was my confusion. Thanks!