代码一：
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<script>
function Car (desc) {
this.desc = desc;
this.color = "red";
}
// Car.prototype = {
// getInfo: function() {
// return 'A ' + this.color + ' ' + this.desc + '.';
// }
// };
//instantiate object using the constructor function
var car=new Car("bmw");
// var car = Object.create(Car.prototype);
// console.log(car.getInfo());
console.log(car instanceof Car);
console.log(car.color);
console.log(car.desc);
</script>
</head>
<body>
</body>
</html>
以上code输出结果为：
true
red
bmw
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<script>
function Car (desc) {
this.desc = desc;
this.color = "red";
}
// Car.prototype = {
// getInfo: function() {
// return 'A ' + this.color + ' ' + this.desc + '.';
// }
// };
//instantiate object using the constructor function
// var car=new Car("bmw");
var car = Object.create(Car.prototype);
// console.log(car.getInfo());
console.log(car instanceof Car);
console.log(car.color);
console.log(car.desc);
</script>
</head>
<body>
</body>
</html>
以上code输出结果：
true
undefined
undefined
问题来了：
通过new+构造函数构建实例，实例能访问构造函数的属性
通过Object.create(prototype)构建实例时，实例对象不能访问构造函数的属性
以上结果出现的理论依据在哪里。找出来