Asserting number of a specific keyword used in Matlab Grader

Hi,

i am currently setting up an assessment in MATLAB Grader. Is there a way to check if a keyword is used only once?

My students are supposed to write a function using exactly one 'for' loop.

Is that possible?

Answer 1

[Uday Pradhan]

You can use "textscan" function to read formatted data from text file or string.

The below code helps you in finding the number of times "for" keyword appears in the function named "myfunction.m" submitted by students:

file = fopen('myFunction.m','r'); 
st = textscan(file,'%s'); 
fclose(file); 
str = st{:}; 
assert(numel(find(strcmp(str,'for'))) <= 1,'Use only one for loop')

This can be kept as a pre - test which will generate a warning if there are multiple "for" keywords in the answer. You may keep a template for the function so that the function name is not tampered with. Hope this helps.

[Cris LaPierre]

Just be careful. This approach is context-unaware. and does not distinguish between comments and code.

Also, pre-tests don't generate warnings. They are correct or incorrect, just like other assessment tests. You can run pre-tests without submitting. However, unless there is a limited number of submissions, there is no advantage to using pre-tests over regular assessment tests.