“\ u2028”unicode字符上的Javascript解析错误 [英] Javascript parse error on '\u2028' unicode character
问题描述
每当我在我的javascript源代码中使用\ u2028字符文字，内容类型设置为text / html; charset = utf-8时，我会收到javascript解析错误。
Whenever I use the \u2028 character literal in my javascript source with the content type set to "text/html; charset=utf-8" I get a javascript parse errors.
示例：
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>json</title>
<script type="text/javascript" charset="utf-8">
var string = '
';
</script>
</head>
<body>
</body>
</html>
如果< meta http-equiv> 遗漏一切按预期工作。我在Safari和Firefox上测试了这个，两者都表现出同样的问题。
If the <meta http-equiv> is left out everything works as expected. I've tested this on Safari and Firefox, both exhibit the same problem.
关于为什么会发生这种情况的任何想法以及如何正确解决这个问题（不删除编码） ？
Any ideas on why this is happening and how to properly fix this (without removing the encoding)?
编辑：
经过一些研究后，具体问题是使用JSONP返回问题字符。然后由浏览器解释，它将u2028作为换行符读取并抛出有关字符串中无效换行符的错误。
After some more research, the specific problem was that the problem character was returned using JSONP. This was then interpreted by the browser, which reads u2028 as a newline and throws an error about an invalid newline in a string.
推荐答案
是的，它是ECMAScript标准（第3版第7.3节）中记录的JavaScript语言的一个特性，即U + 2028和U + 2029字符计为行结尾。因此，JavaScript解析器将以与换行符相同的方式处理任何未编码的U + 2028/9字符。由于你不能在字符串文字中添加换行符，因此会出现语法错误。
Yes, it's a feature of the JavaScript language, documented in the ECMAScript standard (3rd edition section 7.3), that the U+2028 and U+2029 characters count as line endings. Consequently a JavaScript parser will treat any unencoded U+2028/9 character in the same way as a newline. Since you can't put a newline inside a string literal, you get a syntax error.
这是JSON设计中的一个不幸的疏忽：它实际上不是适当的JavaScript子集。原始U + 2028/9字符在JSON中的字符串文字中有效，并且将被 JSON.parse 接受，但在JavaScript本身中则不然。
This is an unfortunate oversight in the design of JSON: it is not actually a proper subset of JavaScript. Raw U+2028/9 characters are valid in string literals in JSON, and will be accepted by JSON.parse, but not so in JavaScript itself.
因此，如果您确定明确地 \ u -escape这些字符，那么使用JSON解析器生成JavaScript代码是安全的。有些人有，有些则没有;许多 \u -escape所有非ASCII字符，这可以避免这个问题。
Hence it is only safe to generate JavaScript code using a JSON parser if you're sure it explicitly \u-escapes those characters. Some do, some don't; many \u-escape all non-ASCII characters, which avoids the problem.
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