How to add only two choices for an input parameter ?

I would like a function to accept only 'string1' or 'string2' for param3 i.e.:

output = fun(param1, param2, param3)

What should I add to param3 ?

Thank you

Answer 1

[Ameer Hamza]

Use assert() to throw error if condition fail

assert(any(strcmp(param3, {'string1', 'string2'})), 'param3 must b string1 or string2')

it will compare param3 to see whether it is 'string1' or 'string2'. If none has detected the function with end an throw an error.

Answer 2

[John D'Errico]

You cannot "add" something to param3.

You CAN test to see if param3 is anything else, and then return an error.