您的位置: 首页  >  IT文章  >  swift语言点评十二-Subscripts

swift语言点评十二-Subscripts

分类: IT文章 • 2024-06-25 18:15:06

Classes, structures, and enumerations can define subscripts, which are shortcuts for accessing the member elements of a collection, list, or sequence.

下标的形式和函数相同，并且set和get合一

subscript(row: Int, column: Int) -> Double

比较：

In addition to simple properties that are stored, properties can have a getter and a setter.

  1. class EquilateralTriangle: NamedShape {
  2. var sideLength: Double = 0.0
  4. init(sideLength: Double, name: String) {
  5. self.sideLength = sideLength
  6. super.init(name: name)
  7. numberOfSides = 3
  8. }
  10. var perimeter: Double {
  11. get {
  12. return 3.0 * sideLength
  13. }
  14. set {
  15. sideLength = newValue / 3.0
  16. }
  17. }
  19. override func simpleDescription() -> String {
  20. return "An equilateral triangle with sides of length (sideLength)."
  21. }
  22. }
  23. var triangle = EquilateralTriangle(sideLength: 3.1, name: "a triangle")
  24. print(triangle.perimeter)
  25. triangle.perimeter = 9.9
  26. print(triangle.sideLength)

相关推荐