javascript - javascript中实例的__proto__与其构造函数的原型(prototype)之间的关系

Question

我编写了代码来为我找出实例的 __proto__ 与其构造函数的原型(prototype)之间的关系:

// Constructor
var Guy = function( name ) {
       this.name = name;
};

// Prototype
var chinese = {
        region: "china",
        myNameIs: function() {
            return this.name;
        }
};

Guy.prototype = chinese;

var he = new Guy( "Wang" );
var me = new Guy( "Do" );

当我测试 me.__proto__ 是否等于 chinese 时，我得到了 false:

console.log( "__proto__ of me is chinese? " + chinese == me.__proto__ ); // logs false

为什么它们不是同一件事？

Answer 1

因为 + 的优先级高于 ==，所以你真的在做...

( "__proto__ of me is chinese? " + chinese ) == me.__proto__

你需要做的是......

"__proto__ of me is chinese? " + ( chinese == me.__proto__ )

或在控制台调用中使用,来传递单独的参数...

"__proto__ of me is chinese? ", chinese == me.__proto__