# Functions with variable length arguments in MATLAB

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.