在HTML中,表格不应该用于布局,这似乎是普遍的观点。

Why?

我从来没有(老实说,很少)看到过支持这一点的有力论据。通常的答案是:

It's good to separate content from layoutBut this is a fallacious argument; Cliche Thinking. I guess it's true that using the table element for layout has little to do with tabular data. So what? Does my boss care? Do my users care?Perhaps me or my fellow developers who have to maintain a web page care... Is a table less maintainable? I think using a table is easier than using divs and CSS.By the way... why is using a div or a span good separation of content from layout and a table not? Getting a good layout with only divs often requires a lot of nested divs. Readability of the codeI think it's the other way around. Most people understand HTML, few understand CSS. It's better for SEO not to use tablesWhy? Can anybody show some evidence that it is? Or a statement from Google that tables are discouraged from an SEO perspective? Tables are slower.An extra tbody element has to be inserted. This is peanuts for modern web browsers. Show me some benchmarks where the use of a table significantly slows down a page. A layout overhaul is easier without tables, see css Zen Garden.Most web sites that need an upgrade need new content (HTML) as well. Scenarios where a new version of a web site only needs a new CSS file are not very likely. Zen Garden is a nice web site, but a bit theoretical. Not to mention its misuse of CSS.

我对使用divs + CSS而不是表的良好参数非常感兴趣。


当前回答

508符合性-屏幕阅读器能够理解你的标记。 等待呈现——直到</table>元素结束,表格才会在浏览器中呈现。

其他回答

我将一个接一个地看你的论点,并试着指出其中的错误。

将内容与布局分开是很好的 但这是一个错误的论点;陈词滥调的思考。

It's not fallacious at all because HTML was designed intentionally. Misuse of an element might not be completely out of question (after all, new idioms have developed in other languages, as well) but possible negative implications have to be counterbalanced. Additionally, even if there were no arguments against misusing the <table> element today, there might be tomorrow because of the way browser vendors apply special treatment to the element. After all, they know that “<table> elements are for tabular data only” and might use this fact to improve the rendering engine, in the process subtly changing how <table>s behave, and thus breaking cases where it was previously misused.

那又怎样?我的老板在乎吗?我的用户关心吗?

视情况而定。你的老板是尖头发吗?那他可能不在乎。如果她有能力,那么她就会在乎,因为用户会在乎。

也许我或我的开发伙伴谁必须维护一个网页关心…表是否更难维护?我认为使用表格比使用div和css更容易。

大多数专业的web开发人员似乎反对你[需要引用]。事实上,表的可维护性较差,这是显而易见的。使用表格进行布局意味着更改公司布局实际上意味着更改每个页面。这可能会非常昂贵。另一方面,明智地将语义上有意义的HTML与CSS结合使用可能会将此类更改限制在CSS和所使用的图片上。

顺便说一下……为什么使用div或span可以很好地将内容与布局分开,而不是表格?只有div的良好布局通常需要大量嵌套的div。

深度嵌套<div>是反模式,就像表布局一样。优秀的网页设计师不需要太多这样的东西。另一方面,即使是这样深嵌套的div也没有很多表布局的问题。事实上,它们甚至可以通过逻辑地将内容划分为多个部分来构成语义结构。

代码的可读性 我觉得正好相反。大多数人懂html,很少人懂css。这是简单的。

“大多数人”不重要。专业人士。对于专业人士来说,表格布局比HTML + CSS带来更多的问题。这就像是说我不应该使用GVim或Emacs,因为记事本对大多数人来说更简单。或者我不应该使用LaTeX,因为MS Word对大多数人来说更简单。

SEO最好不要使用表格

我不知道这是不是真的,也不会把它作为一个论点,但它是合乎逻辑的。搜索引擎搜索相关数据。虽然表格数据当然可能是相关的,但它很少是用户搜索的内容。用户搜索页面标题或类似突出位置中使用的术语。因此,将表格内容排除在过滤之外,从而大幅减少处理时间(和成本!)是合乎逻辑的。

表比较慢。 必须插入一个额外的tbody元素。这对于现代网络浏览器来说是微不足道的。

额外的元素与表变慢无关。另一方面,表的布局算法要困难得多,浏览器通常必须等待整个表加载后才能开始布局内容。此外,缓存布局将不起作用(CSS可以很容易地缓存)。所有这些都在前面提到过。

向我展示一些使用表会显著降低页面速度的基准测试。

不幸的是,我没有任何基准测试数据。我自己也会感兴趣,因为这个论点确实缺乏一定的科学严谨性。

大多数需要升级的网站也需要新的内容(html)。一个新版本的网站只需要一个新的css文件的场景是不太可能的。

Not at all. I've worked on several cases where changing the design was simplified by a separation of content and design. It's often still necessary to change some HTML code but the changes will always be much more confined. Additionally, design changes must on occasion be made dynamically. Consider template engines such as the one used by the WordPress blogging system. Table layouts would literally kill this system. I've worked on a similar case for a commercial software. Being able to change the design without changing the HTML code was one of the business requirements.

Another thing. Table layout makes automated parsing of websites (screen scraping) much harder. This might sound trivial because, after all, who does it? I was surprised myself. Screen scraping can help a lot if the service in question doesn't offer a WebService alternative to access its data. I'm working in bioinformatics where this is a sad reality. Modern web techniques and WebServices have not reached most developers and often, screen scraping is the only way to automate the process of getting data. No wonder that many biologists still perform such tasks manually. For thousands of data sets.

无论如何,这并不是一个明确的论点,但是对于CSS,你可以使用相同的标记并根据介质改变布局,这是一个很好的优势。例如,对于打印页面,您可以安静地抑制导航,而不必创建打印机友好的页面。

使用表格布局的工具可能会因为创建布局所需的大量代码而变得异常沉重。SAP的Netweaver Portal默认使用TABLE来布局页面。

在我目前的工作中,生产SAP门户有一个主页,它的HTML超过60K,有7个表那么深,在页面中有3次。再加上Javascript,误用了16个iframe,其中有类似的表格问题,CSS过重等,页面重量超过5MB。

花点时间降低页面重量,这样你就可以利用带宽与用户进行互动,这是值得的。

一张桌子来布置也不错。但大多数情况下,仅靠一张表是无法得到所需的布局的。很快你就有了2到3个嵌套表。这变得非常麻烦。

It IS a LOT harder to read. That's not up to opinion. There's just more nested tags with no identifying marks on them. Separating content from presentation is a good thing because it allows you to focus on what you're doing. Mixing the two leads to bloated pages that are hard to read. CSS for styles allows your browser to cache the files and subsequent requests are much faster. This is HUGE. Tables lock you into a design. Sure, not everyone needs the flexibility of CSS Zen Garden, but I've never worked on a site where I didn't need to change the design a little bit here and there. It's much easier with CSS. Tables are hard to style. You don't have very much flexibility with them (i.e. you still need to add HTML attributes to fully control a table's styles)

我大概有4年没有用表格来处理非表格数据了。我没有回头。

我真的很想建议你阅读Andy Budd的《CSS Mastery》。棒极了。

图片在ecx.images-amazon.com http://ecx.images-amazon.com/images/I/41TH5NFKPEL._SL500_BO2,204,203,200_PIsitb-dp-500-arrow,TopRight,45,-64_OU01_AA240_SH20_.jpg

我相信这是一个与普遍问题有关的问题。HTML诞生时,没有人能预见到它的广泛应用。另一项在自身成功的重压下几乎崩溃的技术。当HTML页面用vi在绿色文本终端上编写时,向页面访问者显示数据所需要的只是一个TABLE,而且大多数数据都是以表格形式显示的。

我们都知道事物是如何进化的。相对来说,table最近已经过时了,但是有很多理由更喜欢基于div和CSS的布局(可访问性不是最后一个)。当然我不能写一个CSS来拯救我的生命:-),我认为图形设计专家应该总是在手边。

也就是说……即使在现代网站中,也有许多数据应该在表格中显示。