Matlab Does Not Display Code Folding

57 views (last 30 days)
The line to expand/collapse the code disappears after I edited the script with text. The code fielding option is turned on in preferences. Is there any way to get it back?
matthew schwarz
matthew schwarz on 9 Jan 2022
Edited: matthew schwarz on 9 Jan 2022
So i had a similar problem to OP, that others who find themselves here might find useful.
I currently use the hack
Stuff i want folded
However Ctrl+Shift+. was not folding code and i could not see + in the margin despite all boxes in settings ticked.
You have to right click on the margin/breakpoint and look for "Show Code Folding Margin".
Now the + appears where you can fold code.

Sign in to comment.

Accepted Answer

Steven Lord
Steven Lord on 4 Apr 2016
In my experience usually that means that there's some syntactic error in the file that prevents it from being a valid MATLAB program file. Look in the upper-right corner; do you see a red square? If so, Code Analyzer is telling you that there's an error that WILL prevent the script / function / class from executing and there should be a red line in the right margin that will indicate where it believes the error to be. Correct the error to make the file a valid MATLAB program file and you should be able to fold sections of it again.
Steven Lord
Steven Lord on 7 Nov 2018
Lenny Cabibbo, check the upper-right corner of the Editor as I described in my original answer. Likely your code is not syntactically valid, so MATLAB would not know how (or how much) to fold.
Consider the case of two nested for loops with one end.
for k = 1:10
for j = 2:5
x(k) = k;
y(k) = k.^j;
Should MATLAB fold from the line "for j = 2:5" until the line "end", assuming that the end keyword was intended to end that for loop and leaving the outermost one unterminated? That would be incorrect if the missing end statement was supposed to be before the disp line.
Or should MATLAB fold from "for k = 1:10" to the "end", being "greedy" to try to fold as much code as possible?
Make your code syntactically valid and code folding should be enabled.

Sign in to comment.

More Answers (1)

David Tanis
David Tanis on 8 Nov 2020
Edited: David Tanis on 8 Nov 2020
Hi, So building on this question: How come matlab suddenly decided overnight there were too many errors? And more importantly, how can I fix it quickly? My whole code was based on a sort of improvised foldable userinterface, that has now disappeared. To be clear, my code wasnt made to run in one go, only code sections were intended to be viable.
Any help would be much appreciated.
  1 Comment
David Tanis
David Tanis on 8 Nov 2020
I solved it: I left a 'switch' somewhere unattended.

Sign in to comment.


Find more on Get Started with MATLAB in Help Center and File Exchange


Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by