了解一下js创建类的方式

**总结一下js的类的创建方式和原型链 **

利用fuction 创建 function initCar(){ let car = new Object; car.size = 'big'; car.money = 30000; car.see = function(){ alert('see car'); } return car; } //创建 let bsj = initCar(); let bmw =initCar(); 混合的构造函数/原型方式 function Car(sColor,iDoors,iMpg) { this.color = sColor; this.doors = iDoors; this.mpg = iMpg; this.drivers = new Array("Mike","John"); } Car.prototype.showColor = function() { alert(this.color); }; var oCar1 = new Car("red",4,23); var oCar2 = new Car("blue",3,25); oCar1.drivers.push("Bill"); alert(oCar1.drivers); //输出 "Mike,John,Bill" alert(oCar2.drivers); //输出 "Mike,John"

3、动态原型方法

function Car(sColor,iDoors,iMpg) { this.color = sColor; this.doors = iDoors; this.mpg = iMpg; this.drivers = new Array("Mike","John"); //如果没有给默认方法，则设置，后期不会再设置 if (typeof Car._initialized == "undefined") { Car.prototype.showColor = function() { alert(this.color); }; Car._initialized = true; } }