【Swift 60秒】70 - Static properties and methods

0x00 Lesson

All the properties and methods we’ve created so far have belonged to individual instances of structs, which means that if we had a Student struct we could create several student instances each with their own properties and methods:

struct Student {
	var name: String
	init(name: String) {
		self.name = name
	}
}
let ed = Student(name: "Ed")
let taylor = Student(name: "Taylor")

You can also ask Swift to share specific properties and methods across all instances of the struct by declaring them as static.

To try this out, we’re going to add a static property to the Student struct to store how many students are in the class. Each time we create a new student. we’ll add one to it:

struct Student {
	static var classSize = 0
	var name: String
	init(name: String) {
		self.name = name
		Student.classSize += 1
	}
}

Because the classSize property belongs to the struct itself rather than instances of the struct. we need to read it using Student.classSize:

print(Student.classSize)

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