Accepting parameters
Functions become more powerful when they can be customized each time you run them. Swift lets you send values to a function that can then be used inside the function to change the way it behaves. We’ve used this already – we’ve been sending strings and integers to the print() function, like this:
print("Hello, world!")Values sent into functions this way are called parameters.
To make your own functions accept parameters, give each parameter a name, then a colon, then tell Swift the type of data it must be. All this goes inside the parentheses after your function name.
For example, we can write a function to print the square of any number:
func square(number: Int) {
print(number * number)
}That tells Swift we expect to receive an Int, and it should be called number. This name is used both inside the function when you want to refer to the parameter, but also when you run the function, like this:
square(number: 8)
SPONSORED ViRE offers discoverable way of working with regex. It provides really readable regex experience, code complete & cheat sheet, unit tests, powerful replace system, step-by-step search & replace, regex visual scheme, regex history & playground. ViRE is available on Mac & iPad.
Sponsor Hacking with Swift and reach the world's largest Swift community!
