你真的需要指定类型属性吗?
可能重复:
为什么写<脚本类型=“text/javascript”>什么时候服务器设置mime类型?
我不久前阅读了Dive into HTML5,最近又阅读了它的语义章节.我注意到它建议 not 在 script
和 style
上使用 type="..."
属性,因为:
I read Dive into HTML5 a while back, and read its semantics chapter again just recently. I noted it advises not to use type="..."
attributes on script
and style
, because:
- MIME 类型应由服务器发送,
- JS 和 CSS 是默认设置,
- 浏览器不在乎.
但是,我认为在 script
和 中包含
标签.假设服务器被正确配置为发送正确的 MIME 类型,除了显式之外,还有其他原因使用这些吗?type
属性(或者,恐怖,language
)仍然是常见的做法>style
However, I see it is still common practice to include type
attributes (or, horror, language
) on both script
and style
tags. Assuming the server is properly configured to send the correct MIME types, are there reasons for using these other than being explicit?
编辑:这明确是关于 HTML5,而不是 XHTML.
EDIT: This is explicitly about HTML5, not XHTML.
推荐答案
大多数人习惯于 HTML 4/XHTML 及之前的版本,这些元素需要 type
属性.
Most people are used to HTML 4/XHTML and before, where the type
attribute is required for these elements.
关于 HTML 5,这些确实是可选的,并且规范给出了默认值,具体取决于元素.
In regards to HTML 5, these are indeed optional and the spec gives a default, depending on the element.
对于 脚本
标签,默认为 text/javascript
:
如果语言不是text/javascript"所描述的,那么 type 属性必须存在
If the language is not that described by "text/javascript", then the type attribute must be present
对于style
标签,默认为 text/css
:
type 属性的默认值是text/css".
The default value for the type attribute, which is used if the attribute is absent, is "text/css".
所以,正如你所说,不需要.但是,不能总是依赖浏览器支持和服务器设置 - 明确是一个好主意,因为它可以避免此类问题.
So, not needed, as you stated. However, browser support and server setups can't always be relied on - being explicit is a good idea as it avoids such problems.
当然,并不是所有的浏览器都支持 HTML 5——那些不支持 HTML 5 的浏览器将使用需要该属性的早期版本,并且您的 javascript/css 可能无法在此类浏览器中解析,这意味着您最终没有旧浏览器上的 CSS 或 javascript,当向后兼容的简单解决方案是添加属性时.
And of course, not all browsers out there support HTML 5 - those that don't will use an earlier version where the attribute is required and your javascript/css might not get parsed in such browsers, meaning you end up with no CSS or javascript on older browsers, when a simple solution for backwards compatibility is to add the attribute.
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