除了编码风格之外,还有任何优点/缺点:
Circle.prototype = { radius : 10};
Object.defineProperty(Circle.prototype, 'circumference', {
get: function() { return 2*Math.PI*this.radius; }
});
VS
Circle.prototype = {
radius : 10,
get circumference() { return 2*Math.PI*this.radius; }
}