关于Javascript继承在es5到es6改变

再重温下之前继承的实现：

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
var inherits = function(ctor, superCtor) {
  ctor.super_ = superCtor;
  ctor.prototype = Object.create(superCtor.prototype, {
    constructor: {
      value: ctor,
      enumerable: false,
      writable: true,
      configurable: true
    }
  });
};
function Point(x, y) {
  this.x = x;
  this.y = y;
}
Point.prototype.toString = function() {
  return '(' + this.x + ', ' + this.y + ')';
}
function ColorPoint(x, y, color) {
  Point.call(this, x, y); 
  this.color = color;
}
inherits(ColorPoint, Point);
ColorPoint.prototype.toString = function() {
  return this.color + ' ' + ColorPoint.super_.prototype.toString.call(this); 
}

然而es6则可以这么写

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
class Point {
  constructor(x, y) {
    this.x = x;
    this.y = y;
  }
  toString() {
    return '(' + this.x + ', ' + this.y + ')';
  }
}
class ColorPoint extends Point {
  constructor(x, y, color) {
    super(x, y); 
    this.color = color;
  }
  toString() {
    return this.color + ' ' + super.toString(); 
  }
}

显然es6的写法更加清晰，隐去了Javascript硬去使用prototype和call的实现细节。但是es6并没有完全按照Java ,C++面向对象的语法来实现，
只是对于原型继承的一个语法糖。