JavaScript：好的部件名称/字符串铁路图令人困惑 [英] JavaScript: The Good Parts Names/Strings railroad diagrams confusing

问题描述

我开始阅读JavaScript：好的零件书，并在第一页（如果确切地说是7和9）被铁路图弄糊涂了。

I started reading JavaScript: The Good Parts book and became confused at first pages (7 and 9 if be exact) by the railroad diagrams.

有图表名称和字符串文字。 （您可以在此处查看图表）

There are diagrams for the name and the string literal. (you can see the diagrams here)

我知道JavaScript中的名字可以以字母开头，也可以以下划线或$符号开头。按照本书的图表，它只能从字母开始。

As I know names in JavaScript can start with letters as well as with underscore or even '$' symbol. Following by the book's diagram it can starts only from letters.

对于字符串文字，假设您想要表示字符串：\\。< br>
按照图表后面是不可能的（似乎在转义字符之后，除了之外的任何unicode字符，并且需要\和contol。

For the string literal, imagine that you want to represent string like that: "\\".
Following by the diagram it's not possible(seems like after the "escaped character" the "any unicode character except " and \ and contol" is required.

这些是书中的错误吗？或者我错过了什么？

Are those an errors in the book? Or I miss something?

推荐答案

善良一书中描述的语言部件不是JavaScript而是它的一部分 - 你可以称之为Crockford的JavaScript.Crockford引入了新的语法限制。其中一个限制是名称不能以 $ 开头或 _ 。

The language described in the book "The Good Parts" is not JavaScript but a subset of it - you can call it "Crockford's JavaScript". Crockford introduces new syntax restrictions. One of those restrictions is that names cannot start with $ or _.

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