How can I determine a function's argument count at runtime in Flex 3?

Question

I want to pass an optional data parameter to some callbacks, but only to callbacks that support a single parameter; right now, I have a moderately-sized code base of callbacks that cannot accept a parameter at all. How can I check what parameters a Function object supports?

Answer 1

Function is an Object. Every function has a read-only property named length that stores the number of parameters defined for the function. Use it.