CODEWITHSUNDEEP
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Giuseppe
Giuseppe

Reputation: 507

How to terminate a function without 'Output argument "varargout" not assigned 'error?

I have a function with a variable number of arguments and outputs, and I want it to exit at a certain point if there is an additional argument:

function [out, varargout] = myfunction(a,varargin)

    % do stuff
    out = 1;

    if nargin > 1
       return
    end

    % do extra stuff if there is no additional argument
    varargout{1} = 'optional output';

end

I get the error

Output argument "varargout" not assigned during call to "C:\...\myfunction"

How can I solve this?

Upvotes: 3

Views: 3610

Answers (1)

Stewie Griffin
Stewie Griffin

Reputation: 14939

How about something like this?

function varargout = my_function(a,varargin)

    % do stuff
    varargout{1} = 1;

    if nargin > 1
        if nargout > 1
            varargout(2:nargout) = {[]};
        end
       return
    end

    % do extra stuff if there is no additional argument
    varargout{2} = 'optional output';

end

Test:

[a b] = my_function(2)
a =
     1
b =
optional output

[a b] = my_function(2,3)
a =
     1
b =
     []

The problem is, you can't call a function with more outputs than it creates. Therefore, calling you original function a = my_function(2,3) would work fine, while [a b] = my_function(2,3) will cause an error.

Thus you have (at least) two alternatives:

  1. Make sure the number of output and input variables match every time you execute the function.

  2. Do as I did above.

Upvotes: 3

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