javascript：/ * @ @ * /是什么意思？ [英] javascript: what does /*@ @*/ mean?

问题描述

有人可以解释html5shim脚本的开头和结尾如何工作吗？

Can someone explain how the beginning and end of the html5shim script works?

脚本以 / * @ 并以 @ * / 结尾，如下所示：

the script starts with /*@ and ends with @*/like this:

/*@cc_on(function(a,b){function ........ (this,document);@*/

/ * @ @ * / 在做什么？

我希望/ * * /序列注释掉它们之间的所有行，但是由于脚本执行了，所以这里不是这种情况吗？我很困惑。

I would expect the /* */ sequence to comment out all lines in between them, but since the script executes, that cant be the case here? I'm confused.

位于：

http://html5shim.googlecode.com/svn/trunk/html5.js

推荐答案

IE的JScript支持条件编译，这是一种在注释中隐藏特定于浏览器的特殊信息的技巧，即 /*@...@*/ 是一个不寻常的字符序列，因此可以安全地重新使用t来介绍这项新的语法级功能。

IE's JScript supports ‘conditional compilation’, a trick of hiding special browser-specific information in comments. The idea is that /*@...@*/ is such an unusual sequence of characters that it is safe to repurpose it to introduce this new syntax-level feature.

html5shiv使用它来创建一段代码，甚至不会尝试在大多数浏览器上运行（就像您做到了，会将整个内容解释为一个值得称赞的内容），但是对IE而言具有特殊含义。

html5shiv uses it to create a piece of code that won't even try to run on most browsers (which, like you did, will interpret the whole thing as a commend), but which has special meaning to IE.

此处为MS文档。没有其他JS引擎支持此功能。通常，您可能更喜欢使用更明确的行为嗅探代码，但是，如果您确实需要检测不会使自身暴露于嗅探的IE功能，则它会很方便。

MS doc here. No other JS engine supports this. Typically you might favour more explicit behaviour-sniffing code instead, but if you really need to detect an IE feature that doesn't expose itself to sniffing otherwise, it can be handy.

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