Function Parameters

We can also send data to functions for them to use. In order to do this we have to let the functions know a few things. To start with, those are:

1. That data will be coming in
2. What type of data it will be
3. A variable name to use to hold the incoming data

The way we do that is to assign a variable inside the parenthesis after the function name. The format is similar to what we've used to assigning variable so far but we remove the let, =, and the value.

So instead of this:

let alfa: i32 = 3

we'd pull out just this part:

alfa: i32

To use that in a function named widget we'd write this:

fn widget(alfa: i32) {
  println!("I am alfa");
}

TODO: Combine this with the next page since it doesn't really make sense to show the incoming parameter but not use it.