JavaScript的prototype是什么？

// 缺省值为：Rabbit.prototype = { constructor: Rabbit }
function Rabbit() { }
alert(Rabbit.prototype.constructor == Rabbit)

// rabbit继承了constructor
let rabbit = new Rabbit();

// 输出结果：true
alert(rabbit.constructor == Rabbit);

function Rabbit() { }

// 1、错误：这会覆盖整个 Rabbit.prototype，
// Rabbit.prototype.constructor不能正确指向Rabbit
Rabbit.prototype = {
    jumps: true
};
// 输出：false
alert(Rabbit.prototype.constructor === Rabbit);

function Rabbit() { }

// 1、正确：采用添加操作
// Rabbit.prototype.constructor==Rabbit没有被破坏
Rabbit.prototype.jumps = true
// 输出：true
alert(Rabbit.prototype.constructor === Rabbit);

// 2、正确：采用手动添加操作，等同于上面
Rabbit.prototype = {
    jumps: true,
    constructor: Rabbit
};
alert(Rabbit.prototype.constructor === Rabbit);

function Rabbit(name) {
    this.name = name;
    alert(name);
}

let rabbit = new Rabbit("White Rabbit");

// constructor默认指向函数本身，上面和下面都是调用函数Rabbit创建对象
let rabbit2 = new rabbit.constructor("Black Rabbit");