class Subjects {
var physics: String
init(physics: String) {
self.physics = physics
}
}
class Chemistry: Subjects {
var equations: String
init(physics: String, equations: String) {
self.equations = equations
super.init(physics: physics)
}
}
class Maths: Subjects {
var formulae: String
init(physics: String, formulae: String) {
self.formulae = formulae
super.init(physics: physics)
}
}
// [AnyObject] 类型的数组
let saprint: [AnyObject] = [
Chemistry(physics: "固体物理", equations: "赫兹"),
Maths(physics: "流体动力学", formulae: "千兆赫"),
Chemistry(physics: "热物理学", equations: "分贝"),
Maths(physics: "天体物理学", formulae: "兆赫"),
Maths(physics: "微分方程", formulae: "余弦级数")]
let samplechem = Chemistry(physics: "固体物理", equations: "赫兹")
print("实例物理学是: \(samplechem.physics)")
print("实例方程式: \(samplechem.equations)")
let samplemaths = Maths(physics: "流体动力学", formulae: "千兆赫")
print("实例物理学是: \(samplemaths.physics)")
print("实例公式是: \(samplemaths.formulae)")
var chemCount = 0
var mathsCount = 0
for item in saprint {
// 类型转换的条件形式
if let show = item as? Chemistry {
print("化学主题是: '\(show.physics)', \(show.equations)")
// 强制形式
} else if let example = item as? Maths {
print("数学主题是: '\(example.physics)', \(example.formulae)")
}
}
var exampleany = [Any]()
exampleany.append(12)
exampleany.append(3.14159)
exampleany.append("Any 实例")
exampleany.append(Chemistry(physics: "固体物理", equations: "兆赫"))
for item2 in exampleany {
switch item2 {
case let someInt as Int:
print("整型值为 \(someInt)")
case let someDouble as Double where someDouble > 0:
print("Pi 值为 \(someDouble)")
case let someString as String:
print("\(someString)")
case let phy as Chemistry:
print("主题 '\(phy.physics)', \(phy.equations)")
default:
print("None")
}
}
