Swift学习_Any和AnyObject的类型转换

Swift

1.AnyObject

AnyObject表示任何类型的实例

class Person{
    
  var name:String?
  init(name:String) {
        
      self.name = name
  }
}

class Employee: Person {
    
    var company:String?
    init(name:String,company:String) {
        
        self.company = company
        super.init(name: name)
    }
}

class Student: Person {
    
    var school:String?
    init(name:String,school:String) {
        
        self.school = school
        super.init(name: name)
    }
}


let employee1 = Employee(name:"张三",company:"apple公司")
let employee2 = Employee(name:"李四",company:"google公司")
let members:[AnyObject] = [employee1,employee2]

for item in members{
    
    let employee = item as!Employee
    print("员工公司：\(String(describing: employee.company))")
}

2.Any类型

Any类型可以表示任何类型，比如类，函数，Int，String，元祖等

var things = [Any]()
things.append(42)
things.append("hello")
things.append((2,5))
things.append(Employee(name:"梅梅", company: "中国航天公司"))
things.append({(name:String) -> String in "你好,\(name)"})

for thing in things{
    
    switch thing{
        
        case let someInt as Int:
            print("整数：\(someInt)")
        case let someString as String:
            print("字符串:\"\(someString)\"")
        case let (x,y) as (Int,Int):
            print("元组类型：\(x,y)")
        case let employee as Employee:
            print("员工:\(String(describing: employee.name)),公司:\(String(describing: employee.company))")
        case let stringConverter as(String)->String:
            print(stringConverter("小明"))
        default:
            print("其他")
    }
}

注意
在switch语句的case语句里使用类型转换操作符as而不是as!，来检查和转换到一个明确的数据类型，在switch case语句中这样的检查总是安全的

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Any和AnyObject的类型转换结果输出

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代码已上传至git：

--> 传送门：Swift_基本语法

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