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)
0x01 我的小作品
欢迎体验我的作品之一:小笔记-XNote
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