Hello. In one of Paul's Review Quiz questions and the result is that it is "valid Swift".

I don't know what "return" is doing in this example. Is this shorthand for "return nil"?

func test(number: Int?) {
  guard let number = number else
  { return }
    print("Number is \(number)")
   }
   test(number: 42)

Return exits the function early

"Return exits the function early". Okay, got it.

What would happen in the funcion if the integer was nil?

test(number: nil)

Exactly that! The function will be exited early in the guatd statement, meaning the rest of the function isn't executed. So in this case, the print statement will not be run!

your function returns void i.e. nothing. guard statements is there to check if its nil or not. if var provided is nil then else block of the guard statement is executed. and there you wrote return which means just return from the function without trying to do anything else.