swift类型检查（is操作符）

类型检查操作符 is 可以检查一个对象是不是某个类的对象。

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

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

class Stutent:Person{
    var age:Int
    init (age:Int, name:String){
        self.age = age
        super.init(name: name)
    }
}

let tea = Teacher(name:"老师", school:"北工大")
let stu = Stutent(age:23, name:"学生")
let array = [tea, stu];
for item in array{
    if item is Teacher{
        print("1",item.name)
    }else if item is Stutent{
        print("2",item.name)
    }
}

控制台：

1 老师
2 学生