Here is a small MATLAB script that demonstrates creating a function with variable length arguments.

function rval=testfn(varargin)
  rval=0;
  for i=1:nargin
  display(varargin(i));
end

executing this shall output -

>> testfn('Hello','World',1,2,3,[4,5;6,7])

    'Hello'

    'World'

    [1]

    [2]

    [3]

    [2x2 double]

Now, if we want a function that returns the sum of all the arguments -

function rval=testfn(varargin)
  rval=0;
  for i=1:nargin
    rval=rval+varargin{i};
  end

>> testfn(1,2,3,4,5)

ans =

    15

Notice varargin{i}. Since it is not possible to predict the data type that shall be passed to the function, MATLAB uses the cell data type. If we attempt to pass a string along with numbers, we shall get an exception. Also -

>> testfn(1,2,3,[4,5;6,7])

ans =

    10    11
    12    13

If this is not the result you are looking for, you will have to run a lot of checks on the input data before you use it. See MATLAB help page on Data Type Identification. This is a lot of overhead to process. More so, if your function is in a loop and is being called multiple times. So it is best not to use this unless you have no other viable alternatives.