Javascript：获取单个属性名称 [英] Javascript: Getting a Single Property Name

问题描述

给出这样的对象：

{ name: "joe" }

我想获得值name。我知道我可以使用for构造来迭代对象中的属性，但是我将要处理的对象将始终只有一个键：值对，我不知道属性的名称。进一步说明：

I want to get the value "name". I know I can use the for construct to iterate over the properties in an object, but the objects I'll be dealing with will always have a single key:value pair, and I won't know the name of the property. To further illustrate:

var a = { age: 24 };
console.log(myFunc(a)) // Displays "age"

var b = { job: "cook" };
console.log(myFunc(b)) // Displays "job"

有没有无论如何要做到这一点而不迭代对象？我也想在纯Javascript中这样做。没有框架/库。

Is there anyway to do this without iterating over the object? Also I'd like to do this in pure Javascript. No frameworks/libs involved.

推荐答案

最好使用 .hasOwnProperty 确保您没有从Object原型返回属性：

It is good practice to use .hasOwnProperty to ensure you aren't returning a property from the Object prototype:

function myFunc(obj) {
    for (var prop in obj) {
        if (obj.hasOwnProperty(prop)) return prop;
    }
}

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