How to write a fucntion which we don't know how many "in" values will be needed?

I want to know how to write first line of a function which we cant tell how many variables will be "inputed".

example :

for equation 1 :

function[] = in(c1,c2,c3)

for equation 2:

function[] = in(c1,c2,c3,c4)

Answer 1

[madhan ravi]

https://www.mathworks.com/help/matlab/ref/varargin.html

[John D'Errico]

Yep. And varargout on the other end.

[madhan ravi]

Thank you @John D‘Ericco ?

[IBM watson]

Thanks all!!

[madhan ravi]

Anytime :)