Swift 类型嵌套

Posted 2020-10-28 qianchia

1、类型嵌套

• Swift 支持类型嵌套，把需要嵌套的类型的定义写在被嵌套的类型的 {} 中。

• Swift 中的枚举类型可以辅助实现特定的类或者结构体的功能。

  struct SchoolUniform {
  
      enum Style: String {                    // 在结构体中嵌套枚举
          case sports = "yundongfu"
          case suit = "zhongshanzhuang"
      }
  
      enum Grade: String {                    // 在结构体中嵌套枚举
          case one = "chuyi"
          case two = "chuer"
          case three = "chusan"
      }
  
      let myStyle: Style
      let myGrade: Grade
  
      func customize() {
          print("my grade: \(myGrade), my style: \(myStyle)")
      }
  }

  let uniform4XiaoMing = SchoolUniform(myStyle: .suit, myGrade: .one)
  uniform4XiaoMing.customize()                // my grade: one, my style: suit