javascript - 什么时候 JavaScript 属性不是标识符？

Question

我正在阅读这篇文章:http://yehudakatz.com/2011/08/12/understanding-prototypes-in-javascript/ .

下面的语句:

Just like when looking up properties, if the property you are definingis an identifier, you can use dot syntax instead of bracket syntax.For instance, you could say man.sex = "male" in the example above.

我在 JavaScript 中查找标识符，因为我对这个语句有点困惑，并找到了这篇文章:http://coderkeen.com/old/articles/identifiers-en.html .它说:

An identifier is regarded as a value which is unique in relation toall the other identifiers in a system.

及以后:

Javascript makes no exclusion and identifiers are used for:

Variable namesFunction namesNames of formal parameters of functions

如标题所示:

我什么时候会得到一个 JavaScript 对象的属性，它不是标识符，因此无法使用 . 语法访问？还是我误读了什么？

Answer 1

var someobject = {};
someobject["I'm a turtle"] = true;

I'm a turtle 绝对不是标识符!