ts中定义类
class Person{ name:string; //属性 前面省略了public关键词 constructor(n:string){ //构造函数 实例化类的时候触发的方法 this.name = n; } run():void{ alert(this.name); }}var p = new Person('lisi');p.run() 
class Person{ name:string; constructor(name:string){ this.name = name; } getName():string{ return this.name; } setName(name:string):void{ this.name = name; }}var p = new Person('lisi');alert(p.getName());p.setName('wanwu');alert(p.getName()); 
继承
class Person{ name:string; constructor(name:string){ this.name = name; } run():string{ return `${this.name}在运动`; }}var p = new Person('lisi');alert(p.run());class Web extends Person{ constructor(name:string){ super(name); } run():string{ return `${this.name}在运动--子类` } work(){ alert(`${this.name}在工作`) }}var w = new Web('wanwu');alert(w.run());w.work(); 
修饰符
- public :公有 在当前类里面、 子类 、类外面都可以访问
- protected：保护类型 在当前类里面、子类里面可以访问 ，在类外部没法访问
- private ：私有 在当前类里面可以访问，子类、类外部都没法访问
public
class Person{ public name:string; constructor(name:string){ this.name = name; } run():string{ return `${this.name}在运动`; }}var p = new Person('lisi');alert(p.run());class Web extends Person{ constructor(name:string){ super(name); } run():string{ return `${this.name}在运动--子类` } work(){ alert(`${this.name}在工作`) }}var w = new Web('wanwu');alert(w.run()); 
protected
class Person{ protected name:string; constructor(name:string){ this.name = name; } run():string{ return `${this.name}在运动`; }}var p = new Person('lisi');alert(p.run());class Web extends Person{ constructor(name:string){ super(name); } run():string{ return `${this.name}在运动--子类` } work(){ alert(`${this.name}在工作`) }}var w = new Web('wanwu');alert(w.run()); 
静态属性 静态方法
class Person{ public name:string; /*公有属性*/ static sex = '男' //静态属性 constructor(name:string){ this.name=name; } run():string{ return `${this.name}在运动` } static print(){ // alert('print方法'+this.name); alert('print方法'+Person.sex); }}var p = new Person('lisi');Person.print(); 
多态
多态:父类定义一个方法不去实现，让继承它的子类去实现，每一个子类有不同的表现
多态属性继承父类有方法，子类也有同样的方法
class Animal{ name:string; constructor(name:string){ this.name = name; } //具体吃什么，不知道，具体吃什么，让继承它的子类去实现，每一个子类的表现不一样 eat(){ console.log('吃的方法') }}class Dog extends Animal{ constructor(name:string){ super(name); } eat(){ return this.name +'吃骨头' }}var d = new Dog('d');alert(d.eat());class Cat extends Animal{ constructor(name:string){ super(name); } eat(){ return this.name +'吃鱼' }}var c = new Cat('c');alert(c.eat()); 
父类有方法，子类没有同样的方法
class Animal{ name:string; constructor(name:string){ this.name = name; } //具体吃什么，不知道，具体吃什么，让继承它的子类去实现，每一个子类的表现不一样 eat(){ console.log('吃的方法') }}class Dog extends Animal{ constructor(name:string){ super(name); } eat(){ return this.name +'吃骨头' }}var d = new Dog('d');alert(d.eat());class Cat extends Animal{ constructor(name:string){ super(name); } // eat(){ // return this.name +'吃鱼' // }}var c = new Cat('c');alert(c.eat()); 
抽象类
抽象类:它是提供其它继承的基类，不能直接被实例化
- abstract关键字定义抽象方法，抽象类中的抽象方法不包含具体实现并且必须在派生类中实现
- abstract抽象方法只能放在抽象类里面
- 抽象类和抽象方法用来定义标准，标准:Animal这个类要求它的子类必须包含相同的方法，如eat()
直接被实例化,报错
abstract class Animal{ public name:string; constructor(name:string){ this.name = name; } abstract eat():any; run(){ console.log('运动') }}var a = new Animal(); 
父类定义的抽象方法，子类没有定义，报错
abstract class Animal{ public name:string; constructor(name:string){ this.name = name; } abstract eat():any; run(){ console.log('运动') }}class Dog extends Animal{ constructor(name:string){ super(name); } // eat(){ // console.log(this.name+'吃骨头') // }} 
正常
类非抽象方法，子类可以不写
abstract class Animal{ public name:string; constructor(name:string){ this.name = name; } abstract eat():any; run(){ console.log('运动') }}class Dog extends Animal{ constructor(name:string){ super(name); } eat(){ console.log(this.name+'吃骨头') }}var d = new Dog('d');d.eat()class Cat extends Animal{ constructor(name:string){ super(name); } eat(){ console.log(this.name+'吃鱼') }}var c = new Cat('c');c.eat() 