Hello,

I've found Ruby very interesting. I like it, but coming from a Java 
background I'm having some problems when it comes to parameters and 
function return values. When I program in Java, I just have a look at 
the method definition and I know what classes I have to pass to the 
method and what class the method will return. And, if I write something 
wrong, the compiler will warn me. Now: how do you do it in Ruby? Do you 
use a special notation to understand what classes are to be passed to 
methods? And: when the parameters of a method change (in number and/or 
type), how do you change the calling code accordingly?

Example:

def mymethod(customer, vendor)
  <some code here>
end

What class do customer and vendor belong? To Customer and Vendor? Or to 
Person? Or are they just strings?
What are the ruturn types?

And when you change the code to:

def mymethod(customer, vendor, times)
  <some code here>
end

do you use "grep" (or any other IDE command) to find all the calling 
code to change it?

Hope this post doesn't end in a flame "java vs ruby". I just want to 
understand how people deal with this things, so that I can get the best 
out of Ruby.