0x00 Lesson
Functions let us re-use code, which means we can write a function to do something interesting then run that function from lots of places. Repeating code is generally a bad idea, and functions help us avoid doing that.
To start with, we’re going to write a function that prints help information for users of our app. We might need this anywhere in our app, so having it as a function is a good idea.
Swift functions start with the func keyword, then your function name, then open and close parentheses. All the body of your function - the code that should be run when the function is requested - is placed inside braces.
Let’s write the printHelp() function now:
func printHelp(){
let message = """
Welcome to MyApp!
Run this app inside a directory of
images and
MyApp will resize them all into
thumbnails
"""
print (message)
}
We can now run that using printHelp() by itself:
printHelp()
Running a function is often referred to as calling a function.
0x01 我的小作品
欢迎体验我的作品之一:小编辑器-XCompiler 在线编辑器~小而巧 App Store 搜索即可~
|