Swift Programming: The Big Nerd Ranch Guide, 3rd Edition

Function Parameters

Functions take on more life when they have parameters. A function’s parameters name the inputs that the function accepts, and 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.

Example 12.2. Using a parameter

func printGreeting() {
     print("Hello, playground.")
}
printGreeting()


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

printPersonalGreeting(name: String) has a single parameter, as indicated in the parentheses directly after the function name. The parameter is called name, and it is an instance of the String type. ...