Clear Filters
Clear Filters

do nothing command in matlab

334 views (last 30 days)
joe khese
joe khese on 22 Feb 2014
Commented: Ron Fredericks on 23 Mar 2023
is there a do nothing command in matlab like the ';' in c and c++. i am trying to write a command that does nothing for a particular condition for example
if (condition)= true; do something; else do nothing; ( in c this would just be ';') end
Pls how can I do this in MATLAB??
  2 Comments
per isakson
per isakson on 29 Apr 2014
Edited: per isakson on 8 May 2014
My "do nothing" function/method reads
function appropriate_name( varargin )
end
Patrik Ek
Patrik Ek on 7 May 2014
That is fair enough, but as seen in the answer there is a much simpler way not requiring a function call. Still if you want to use it, I guess the little overhead it creates disappears in the rest.

Sign in to comment.

Answers (4)

Ernst Kloppenburg
Ernst Kloppenburg on 20 Jul 2017
matlab will accept an empty if body or else body, at least as of R2015b:
if condition
do something
else
% do nothing
end
  1 Comment
Ron Fredericks
Ron Fredericks on 23 Mar 2023
The problem with using a "comment for do nothing" is that you can't set a break point on it during debug session.

Sign in to comment.


the cyclist
the cyclist on 22 Feb 2014
This code will work:
if false
disp('false')
else
;
end
But why would this ever be better than simply having no line at all?
if false
disp('false')
end
Just curious about your use case.
  4 Comments
Patrik Ek
Patrik Ek on 29 Apr 2014
Well I guess it is a matter about taste. As the initial if was inside a switch statement, this may have motivated me to not use too many levels of if and switch. Also by adding an extra if there, it seems like a catch for not getting an error. This may not always be the case since not setting 'myvar' is as valid as the others. However, the calculation time is nothing to talk about (not even sure if there will ever be a difference) and the extra if is even the same number of lines, so I guess that I was overly happy about the do nothing statement.
Ron Fredericks
Ron Fredericks on 30 Jan 2022
We can't set a breakpoint on a comment. So having a line of code like "noop" can be useful for debugging.

Sign in to comment.


Yuxiao Zhai
Yuxiao Zhai on 26 Oct 2022
You could create an anonymous function that takes arbitrary input arguments and outputs an empty array. Then executing this anonymous function is simply equivalent to doing nothing.
h = @(varargin)[];
% At the line where you want to do nothing=============
h();
% =====================================================
You could also feed h with any types of input arguments and it would still do nothing, like
h(1,2,3);
h('Hello world');
h(struct, table, cell(1), datetime);
Good luck

Ron Fredericks
Ron Fredericks on 30 Jan 2022
Edited: Ron Fredericks on 30 Jan 2022
I prefer this line of code as equivalent to "noop" or "do nothing"
disp('') % Does nothing but allows developer to set a breakpoint here.

Community Treasure Hunt

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

Start Hunting!