Function basics

Say you have an app that often needs to print your name. You can write a function to do this:

func printMyName() {

print("My name is Matt Galloway.")

}

The code above is known as a function declaration. You define a function using the func keyword. After that comes the name of the function, followed by parentheses. You’ll learn more about the need for these parentheses in the next section.

After the parentheses comes an opening brace, followed by the code you want to run in the function, followed by a closing brace. With your function defined, you can use it like so:

printMyName()

This prints out the following:

My name is Matt Galloway.

If you suspect that you’ve already used a function in previous chapters, you’re correct! print, which prints the text you give it to the console, is indeed a function.

This leads nicely into the next section, in which you’ll learn how to pass data to a function and get data back in return.