@H_301_1@

class Person {           

    var name: String

    var age: Int

    

    func description() -> String {

        return "\(name) 年龄是: \(age)"

    }

    convenience init () {

        self.init(name: "Tony")

        self.age = 18

    }

    convenience init (name: String) {

        self.init(name: name,age: 18)

    }

    init (name: String,age: Int) {       

        self.name = name

        self.age  = age

    }

}

 

class Student: Person {

    var school: String

    init (name: String,age: Int,school: String) {

        self.school = school

        super.init(name: name,age: age)

    }

    convenience override init (name: String,age: Int) {  

        self.init(name: name,age: age,school: "清华大学")

    }

}

 

class Graduate: Student {    

    var special: String = ""

}