Span and div
All HTML elements have a single function and the name of that function is abbreviated for use as an "HTML tag," and most can or must be used in pairs or in combination with other tags. The most basic use, for example: a
p, paragraph element, should contain a paragraph of text; while an
h1, heading-1 element, should contain the highest-level heading of the page or section.
div are also single function elements, but of a second and third order, reflecting "spanning" and "division" functions, defining the two useful levels of content specification: span defining an area of text to which some change (style class, formatting, content definition, etc.) can be applied immediately "in-line"; while a "div" typically defines a larger area of text of a specific style (defined "look"), type, or section of an HTML page, and can have its own formatting, classes, definitions—and contain an unlimited number of spans. Both are able to take advantage of CSS "programmatic scripting" convention to apply "named classes" that are prior-defined in a CSS statement or associated CSS file. Span and div are the two HTML "functions", then, that are specifically intended to be used to create organization and stylistic areas, without ambiguity.
The code tags were introduced to HTML in the internationalization WG second draft html-i18n on 1995-09-25. However it was not until HTML 4.01 the new element became part of the HTML language and appeared in the HTML 4 W3C Working Draft on 1997-09-17.
Differences and default behavior
There are multiple differences between
span. The most notable difference is how the elements are displayed. In standard HTML, a
div is a block-level element whereas a
span is an inline element. The
div block visually isolates a section of a document on the page, and may contain other block-level components. The
span element contains a piece of information inline with the surrounding content, and may only contain other inline-level components. In practice, the default display of the elements can be changed by the use of Cascading Style Sheets (CSS), however the permitted contents of each element may not be changed. For example, regardless of CSS, a
span element may not contain block-level children.
div elements are used purely to imply a logical grouping of enclosed elements.
There are three main reasons to use
div tags with
Styling with CSS
Perhaps the most common use of
<div> elements is to carry
id attributes in conjunction with CSS to apply layout, typographic, color, and other presentation attributes to parts of the content. CSS does not just apply to visual styling: when spoken out loud by a voice browser, CSS styling can affect speech-rate, stress, richness and even position within a stereophonic image.
For these reasons, and for compatibility with the concepts of the semantic web, discussed below, attributes attached to elements within any HTML should describe their semantic purpose, rather than merely their intended display properties in one particular medium. For example, the HTML in
<span class="red-bold">password too short</span> is semantically weak, whereas
<em class="warning">password too short</em> uses an
em element to signify emphasis, and uses a more appropriate class name. By the correct use of CSS, 'warnings' may be rendered in a red, bold font on a screen, but when printed out they may be omitted, as by then it is too late to do anything about them. Perhaps when spoken they should be given extra stress, and a small reduction in speech-rate. The second example is semantically correct markup, rather than merely presentational.
This kind of grouping and labeling of parts of the page content might be introduced purely to make the page more semantically meaningful in general terms. It is impossible to say how the World Wide Web will develop in years and decades to come. Web pages designed today may still be in use when information systems that we cannot yet imagine are trawling, processing, and classifying the web. Even today's search engines such as Google and others use proprietary information processing algorithms of considerable complexity.
For some years, the World Wide Web Consortium (W3C) has been running a major Semantic Web project designed to make the whole web increasingly useful and meaningful to today's and the future's information systems.
The microformats movement is an attempt to build an idea of semantic
classes. For example, microformats-aware software might automatically find an element like
<span class="tel">123-456-7890</span> and allow for automatic dialing of the telephone number.
Access from code
Less common, but just as important examples of code gaining access to final web pages, and having to use
id attributes to navigate within the page include the use of automatic testing tools. On dynamically generated HTML, this may include the use of automatic page testing tools such as HttpUnit, a member of the xUnit family, and load or stress testing tools such as Apache JMeter when applied to form-driven web sites.
The judicious use of
span is a vital part of HTML and XHTML markup. However, they are sometimes overused.
For example, this:
<ul class="menu"> <li>Main page</li> <li>Contents</li> <li>Help</li> </ul>
... is usually preferable to this:
<div class="menu"> <span>Main page</span> <span>Contents</span> <span>Help</span> </div>
Other examples of the semantic use of HTML rather than
span elements include the use of
fieldset elements to divide up a web form, the use of
legend elements to identify such divisions and the use of
label to identify form
input elements rather than
table elements used for such purposes.
- "HTML/Elements/span - Web Education Community Group". 2013-06-13. Retrieved 2013-11-14.
- Harold, Elliotte Rusty (2008). Refactoring HTML. Addison Wesley. p. 184. ISBN 0-321-50363-5. "There is no simple way to find all the unidentified lists in a site. [...] They can be marked up in dozens of different ways: as paragraphs,
divs, tables, [etc]. Once you've found a list, marking up the individual items is easy. Just use
dlinstead of the current wrapper element. [...] For example to remove the bullets add this rule to the page's CSS stylesheet: [...]"
- Raggett, Dave; Arnaud Le Hors; Ian Jacobs (1999). "Adding structure to forms: the FIELDSET and LEGEND elements". HTML 4.01 Specification. W3C. Retrieved 12 July 2010. "The
FIELDSETelement allows authors to group thematically related controls and labels. Grouping controls makes it easier for users to understand their purpose while simultaneously facilitating tabbing navigation for visual user agents and speech navigation for speech-oriented user agents. The proper use of this element makes documents more accessible."
- van Kesteren, Anne (2010). "HTML5 differences from HTML4". W3C. Retrieved 30 June 2010.