！防止YUI压缩器在压缩时删除注释。 （它只是删除1！而不是。多个！意味着你可以多次压缩而不会丢失评论。）这只是一个扩展，但不是javascript本身的一部分。

The ! prevents YUI compressor from removing the comment when it compresses. (It just removes 1 ! instead. Multiple !'s mean you can compress multiple times without loss of the comment.) It's just an extension, but not part of javascript itself.

文档是此处。搜索'C风格的评论'。

Documentation is here. Search for 'C-style comments'.

此外，我不知道有任何其他压缩机尊重！ Packer ，封闭编译器， shrinksafe 和 jsmin 至少不尊重它。

also, I'm not aware of any other compressors that respect the !. Packer, closure compiler, shrinksafe, and jsmin do not respect it at least.