相关疑难解决方法(0)

我正在尝试使用这些代码行

class Student {
    var name: String
    var age: Int?

    init(name: String) {
        self.name = name
    }

    func description() -> String {
        return age != nil ? "\(name) is \(age) years old." : "\(name) hides his age."
    }
}

var me = Student(name: "Daniel")
println(me.description())
me.age = 18
println(me.description())

上面的代码产生如下

Daniel hides his age.
Daniel is Optional(18) years old.

我的问题是为什么有可选(18)那里,我怎么能删除可选和只是打印

Daniel is 18 years old.