Swift Programming: The Big Nerd Ranch Guide

Function Parameters

Functions begin to take on more life when they have parameters. You use parameters to give a function some inputs. We call these parts of a function “parameters” to indicate that they can change value depending upon the data the caller passes into the function. The function takes the data passed to its parameters to execute a task or produce a result.

Create a function that prints a more personal greeting by using a parameter.

Listing 12.2  Using a parameter

import Cocoa

func printGreeting() {
     print("Hello, playground.")
}
printGreeting()
func printPersonalGreeting(name: String) {
     print("Hello \(name), welcome to your playground.")
}

printPersonalGreeting("Matt")

printPersonalGreeting(_:) takes a single ...