为什么Object.prototype.toString返回[object Object] [英] why Object.prototype.toString return [object Object]

问题描述

我的代码如下所示

var obj = { name: 'John' }
var x = obj.toString();// produce "[object Object]"

alert(x)

我想知道为什么实现Object.prototype.toString返回[object Object]，为什么不实现Object.prototype.toString返回"{name: 'John'}"吗?

i want to know why Object.prototype.toString is implemented to return [object Object] and why It's not implemented to return "{name: 'John'}" ?

推荐答案

有关规范的说明，请参见@Leo和@Joel Gregory的答案.您可以使用JSON.stringify显示对象的内容，例如:

See answers from @Leo and @Joel Gregory for an explanation from the spec. You can display an objects' contents using JSON.stringify, e.g.:

const log = (...args) => document.querySelector("pre").textContent += `${args.join("\n")}\n`;
const obj = { name: 'John' }

log(obj.toString());
log(JSON.stringify(obj));

<pre></pre>

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