//private,protected,public
//public允许在类的内外被调用
//private允许在类内使用
//protected允许在类内及继承的子类中使用

// class M_Person
// {
//     public _name:string;
//     public sayHi()
//     {
//         console.log('hi');
//     }
// }

// class M_Teacher extends M_Person
// {
//     public sayBye()
//     {
//         console.log(this._name);
//     }
// }

// const m_person =new M_Person();
// m_person._name = 'dell';

//constructor
/*
class M_Person
{
    //传统写法
    // //private name:string;
    // //constructor(name:string)
    // constructor(public name:string)
    // {
    //     //this.name = name;
    // }
    //简化写法
    constructor(public name:string){}
}
const _person = new M_Person('dell');
console.log(_person.name);
*/
class L_Person
{
    constructor(public name:string){}
}

class L_Teacher extends L_Person
{
    constructor(public age:number)
    {
        super('a');//必须掉super不然报错
    }
}

const l_teacher = new L_Teacher(11);
console.log(l_teacher.age);
console.log(l_teacher.name);