```这是一个关键字还是字面意思？
为什么JS规格调用this一个关键字而不是文字？
它似乎是字面意思，因为我们可以将其用作价值，或者我缺少什么？
return this
那是什么？
Why JS specs call this a keyword and not a literal?
It more seems to be a literal, because we can use it as a value, or what am I missing?
return this
What is it then?
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这并不重要，但是根据规范是一个关键字：请参见关键字和保留的单词和文字。该规格还使用文本中的“关键字
this”一词，例如（随机选择一个实例），在摘要 getThisenvironment 操作：规范的早期版本为非常明确关于它：
（我的重点。）
继续您问题：
我认为在表达式中使用某些内容与产生价值之间没有任何冲突。
此是一个关键字，您可以用来访问当前执行上下文的环境记录的 this -thisting 的值。rici 在评论中提出了一个很好的观点：他们说他们不考虑
this作为字面意思，因为与（Say）true和false不同，它没有固定的值。文字始终具有相同的值，“ a”始终“ a”，true始终true，<代码> null 始终是null等。但是此在代码中的不同位置具有不同的值。它的作用实际上更像是const，而不是文字。隐式const在范围的环境对象中设置（如果是箭头函数范围）。但是再次：这真的没关系。这是一个保留的词，具有特殊的目的和功能，似乎足以使我们不必担心它是关键字还是字面的（或两者）。 :-)
It doesn't really matter, but it's a keyword according to the specification: See Keywords and Reserved Words and Literals. The spec also uses the phrase "keyword
this" in the text a fair bit, for instance (picking an instance at random), there's this text in the section on the abstract GetThisEnvironment operation:Earlier versions of the specification were quite explicit about it:
(My emphasis.)
Continuing with your question:
I don't think there's any conflict between something being a keyword and producing a value when used in an expression.
thisis a keyword you can use to access the value of the ThisBinding of the environment record for the current execution context (or the nearest one that has one).rici made a really good point in the comments: They said they don't think of
thisas a literal because unlike (say)trueandfalse, it doesn't have a fixed value. Literals always have the same value,"a"is always"a",trueis alwaystrue,nullis alwaysnull, etc. Butthishas different values in different places in the code. It really acts more like aconstthan a literal; an implicitconstset in the scope's environment object (or not, in the case of arrow function scope).But again: It really doesn't matter. It's a reserved word that has a special purpose and function in the language, which seems sufficient that we needn't worry about whether it's a keyword or a literal (or both). :-)