我想要一些简单的例子来展示<div>和<span>的使用。我曾看到它们都被用来用id或类标记页面的一部分,但我感兴趣的是,是否有时会优先使用其中一种而不是另一种。
当前回答
正如在其他回答中提到的,默认情况下div将被呈现为块元素,而span将在其上下文中内联呈现。但两者都没有任何语义价值;它们的存在允许您对任何给定的内容应用样式和标识。使用样式,可以使div像span一样,反之亦然。
div的一个有用的样式是内联块
例子:
http://dustwell.com/div-span-inline-block.html CSS显示:内联vs内联块
我曾在游戏网页项目中使用内联块取得了巨大的成功。
其他回答
这很简单。
span的使用不会影响布局,因为它是内联的(在行中(不应该混淆,因为东西可以被换行)) 使用div会影响布局,里面的内容会出现在新行(block element)中,当你想添加的元素没有特殊的语义,而你想让它出现在新行中时,使用<div>。
“块元素”的意义是隐含的,但从未明确说明。如果我们忽略所有的理论(理论是好的),那么下面是一个语用比较。以下几点:
<p>This paragraph <span>has</span> a span.</p>
<p>This paragraph <div>has</div> a div.</p>
生产:
This paragraph has a span.
This paragraph
has
a div.
这表明div不仅不应该内联使用,而且它根本不会产生想要的效果。
Div是一个块元素 Span是一个内联元素。
这意味着要在语义上使用它们,div应该用于包装文档的各个部分,而span应该用于包装文本、图像等小部分。
例如:
<div>This a large main division, with <span>a small bit</span> of spanned text!</div>
注意,在内联元素中放置块级元素是非法的,因此:
<div>Some <span>text that <div>I want</div> to mark</span> up</div>
...是非法的。
编辑:从HTML5开始,一些块元素可以放在一些内联元素中。请参阅这里的MDN参考,以获得相当清晰的清单。以上仍然是非法的,因为<span>只接受短语内容,而<div>是流内容。
你要求一些具体的例子,所以这是一个从我的保龄球网站,BowlSK:
< div id = "头" > < div id = " userbar " > 嗨,大家好,<span class="username">Chris Marasti-Georg</span> | <a href="/edit-profile.html">Profile</a> | .html < a href = " https://www.bowlsk.com/_ah/logout?..。“>签署< / > < / div > < h1 > < a href = " / " >碗<跨类= >“sk sk < / span > < / > < / h1 > < / div >
Ok, what's going on? At the top of my page, I have a logical section, the "header". Since this is a section, I use a div (with an appropriate id). Within that, I have a couple of sections: the user bar and the actual page title. The title uses the appropriate tag, h1. The userbar, being a section, is wrapped in a div. Within that, the username is wrapped in a span, so that I can change the style. As you can see, I have also wrapped a span around 2 letters in the title - this allows me to change their color in my stylesheet.
还要注意的是,HTML5包含了一组广泛的新元素,这些元素定义了常见的页面结构,如article、section、nav等。
Section 4.4 of the HTML 5 working draft lists them and gives hints as to their usage. HTML5 is still a working spec, so nothing is "final" yet, but it is highly doubtful that any of these elements are going anywhere. There is a javascript hack that you will need to use if you want to style these elements in some older version of IE - You need to create one of each element using document.createElement before any of those elements are specified in your source. There are a bunch of libraries that will take care of this for you - a quick Google search turned up html5shiv.
记住,基本上,它们的自我也不执行任何函数。 它们不仅仅通过标记来确定功能。
它们只能在CSS的帮助下进行定制。
现在回到你的问题:
SPAN标签加上一些样式将是有用的,在一行中,比如在一个段落中,在html中。 这是HTML中的行级或语句级。
例子:
<p>Am writing<span class="time">this answer</span> in my free time of my day.</p>
DIV标签的功能就像上面说的那样,只能在样式的支持下可见,可以容纳大量的HTML代码。
DIV是块级
例子:
<div class="large-time">
<p>Am writing <span class="time"> this answer</span> in my free time of my day.
</p>
</div>
根据您的需求,这两种方法都有使用的时间和情况。
希望我的答案很清楚。 谢谢你!
只是想添加一些历史背景关于span和div是如何产生的
跨度历史:
On July 3, 1995, Benjamin C. W. Sittler proposes a generic text container tag for applying styles to certain blocks of text. The rendering is neutral except if used in conjunction of a stylesheet. There is a debate around versus about readability, meaning. Bert Bos is mentioning the extensibility nature of the element through the class attribute (with values such as city, person, date, etc.). Paul Prescod is worried that both elements will be abused. He is opposed to text mentionning that "any new element should be on an old one" and adding "If we create a tag with no semantics it can be used anywehere without ever being wrong. We must force authors to properly tag the semantics of their document. We must force editor vendors to make that choice explicit in their interfaces."
-来源(w3 wiki)
在RFC草案中引入了span:
首先,一个普通的骗局 需要tainer来携带LANG和BIDI属性 在没有其他要素的情况下;《SPAN ele》 Ment就是为此目的而引入的。
-来源(IETF草案)
div的历史:
DIV元素可用于将HTML文档构造为划分的层次结构。 ... 的支持之前,Netscape就引入了CENTER HTML 3.0 DIV元素。它被保留在HTML 3.2中,因为它具有 广泛的部署。
HTML 3.2规格
In a nutshell, both elements arose out of a need for a more semantically-generic container. Span was proposed as a more generic replacement for a <text> element to style text. Div was proposed as a generic way to divide pages and had the added benefit of replacing the <center> tag for center-aligning content. Div has always been a block element because of its history as a page divider. Span has always been an inline element because its original purpose was text styling and today div and span have both arrived at being generic elements with default block and inline display properties respectively.