Home > Article > Web Front-end > Detailed description of HTML web page header code examples
Detailed description of HTML web page header code examples
- 高洛峰Original
- 2017-03-09 16:15:033220browse
In HTML we generally call this part the head of the web page. Although the content in the header will not be displayed on the page, it can affect the inclusion and sorting of web pages by search engines, as well as various global settings of web pages, which can be said to be crucial
Knowledge point 1: Setting the base URL of the web page in the header information
The essence of the base URL is to uniformly set the attributes of the hyperlink. The base URL tag is 6f6cb83b34cb7f2d6a4aed109317b73a, which has two attributes. href and _target. href is used to set the path of the base URL, and _target is used to set the opening method of the hyperlink.
By adding the base URL, all relative website root addresses in the page can be converted into absolute addresses. When the browser browses the page, the relative website and directory address are appended to the back of the base URL path through the dde6fb694e6711ae5e6f381704c04ae4 tag, thereby converting it into an absolute address. We first create a base.htm and write the HTML code as follows:
The code is as follows:
<html> <head> <title>基底网址的设置</title> <base href="<a href="http://www.php.cn">http://www.php.cn/;/a>" _target="_blank" /> </head> <body> </body> </html>
The base URL is set through the above code. The address of any hyperlink in the Base.htm page will have "http://www.jb51.net" in front of it, which is converted to an absolute address. Moreover, the hyperlinks on the page are opened in new windows.
Knowledge point 2: Meta information tag of header information
Meta information tag is the basic tag of header information. Meta information is detailed in professional web page codes. set up. The meta information tag is 03d0e15baf5b7c9d224e5281b47a68fe, which is a single tag. The information provided by the Meta element is invisible to browsing users and is generally used to define the name, keywords, author, etc. of page information. In an HTML page, a meta tag contains a meta content, and there can be multiple meta elements in an HTML header page.
meta tag attributes are divided into two types: page description attribute (name) and http title information (http-equiv).
name attribute
The name attribute is mainly used to describe the content of the web page and is used for search engine optimization. It must be mastered. Correctly set the name attribute so that the search robots of search engines (such as Google, Baidu) can find and classify. Search engines will generally automatically find meta values to classify web pages. The value of name is as follows:
f35d6e602fd7d0f0edfa6f7d103c1b57keywords. That is, keywords are used to describe the keywords and other information contained in the web page, thereby increasing the probability of being searched by search engines. The writing format is 868e796e9fbb547c5f08e864a7a4df0c, and the value of the content attribute is the specific keyword set by the user. (Generally, multiple keywords can be set, separated by English half-width commas. Search engines limit the number of keywords, so the keyword content should be concise and concise)
2cc198a1d5eb0d3eb508d858c9f5cbdbdescription. It means "description" in Chinese and is used to describe the main content, theme, etc. of a web page. Reasonable settings can also increase the probability of being searched by search engines. The format is 1d8e62438629594295da271bcd833ce1. The content attribute value is the specific description of the page set by the user. It can accommodate up to 1024 characters, but the search engine only displays about the first half of the page. 175 characters.
5bdf4c78156c7953567bb5a0aef2fc53author. Author, used to set the name of the website author, often used by more professional websites. The format is2f08f75aa29a140bf21a293a636e6fa0
23889872c2e8594e0f446a471a78ec4cgenerator. Generator, used to set the name of the website editing tool, is often used on more professional website pages. Format538b3d5f0e855c0cfb2b9e0cf5e20bb8
43ad812d3a971134e40facaca816c822robots. Bots, used to limit how pages are searched. The search engine's search robot continuously retrieves information and builds its own database along the links on the web page (such as http and src links). This meta tag can limit some content from being detected by search engines and reduce the disclosure of some information. The writing format is 9227822c4d117acdb6757241066bd851. The value of this attribute contains 4 commands, namely index, noindex, follow, and nofollow. There are 4 combinations according to the arrangement and combination. The combination of Index and follow can also be called all, and noindex and nofollow can also be called none.
http-equiv attribute
The value of the http-equiv attribute is as follows:
f35d6e602fd7d0f0edfa6f7d103c1b57content-type, content category, use Category and language character set for the settings page. Writing format 9e5b326746919d56ee17268cdd015a6d, the value of the content attribute represents that the page is output in HTML code, and the character set is gb2312 (Simplified Chinese) , for international website development, in order to unify characters, it is recommended to use utf-8.
2cc198a1d5eb0d3eb508d858c9f5cbdbrefresh for charset. Refresh is used to set how long the webpage refreshes itself, or automatically jumps to other pages within a period of time. The first writing format 757080911671a20b1611a7846036206c means interval Refresh once every 30 seconds. The second writing format is 0680a513e2570aa091dfe751f4757d53, which means the page will automatically jump to www.google after 30 seconds. com website
5bdf4c78156c7953567bb5a0aef2fc53expires，中文意思为“到期”，用于设置页面到期时间。一旦网页过期，必须到服务器上重新调用网页。第一种编写格式为67eda0067fee50e170a651aa33e1d252，content值代表网页过期的时间，必须使用GMT时间格式。第二种编写格式为773dc1f8cd63bc6f1079cf90f36c788e，表示多少秒后过期。
23889872c2e8594e0f446a471a78ec4ccache-control，缓存控制。用于禁止在缓存中调用网页，编写格式为6556fc60f75d8651a43a242f406d2590，no-cache代表不允许缓存。
43ad812d3a971134e40facaca816c822set-cookie，设置cookie，用于设置本页面cookie多久过期，编写格式为2d3649584c0d2a047839fd197370b05c，代表到这个时间，cookie将被删除。
知识点三：头部信息实现与CSS及JavaScript混编
CSS负责HTML网页的样式，JaveScript负责HTML网页的动态行为。CSS和JaveScript最常用的融合方式是写入头部信息部分。
f35d6e602fd7d0f0edfa6f7d103c1b57加入CSS只需在头部信息中加入5d116c75ef5ab3f65ecf7feff639cac6531ac245ce3e4fe3d50054a55f265927标签对。范例代码如下
代码如下:
<html> <head> <title>CSS的设置</title> <style type=“text/css”> CSS具体内容 </style> </head> <body> </body> </html>
2cc198a1d5eb0d3eb508d858c9f5cbdb加入JavaScript只需要在头部信息中加入9a116d82a87b65437c19d45bbc7d3a3e2cacc6d41bbb37262a98f745aa00fbf0标签对。范例代码如下：
代码如下:
<html> <head> <title>CSS的设置</title> <style type=“text/css”> CSS具体内容 </style> <script type=“text/javascript”> JavaScript具体内容 </script> </head> <body> </body> </html>
知识点四：常用头部信息功能推荐
f35d6e602fd7d0f0edfa6f7d103c1b57页面切换特效，其中一种特效的编写格式如下：
代码如下:
<meta http-equiv=“page-enter” content=“blendtrans（duration=0.5）”/>
http-equiv属性的值为page-enter时表进入该页面时启用特效，http-equiv属性的值为page-exit时代表退出（离开）该页面时启用特效。
Content属性的值代表特效的种类，这种特效也叫动态滤镜。滤镜种类很多，比如blendtrans就是很常见得一种，效果为淡入淡出，duration值表示效果持续的时间（单位为秒）。
另一种滤镜特效编写格式如下：
代码如下:
<meta http-equiv=“page-enter” content=“revealTrans（duration=6）”/>
动态滤镜revealTrans也可用于页面进入与退出效果。Duration表示滤镜特效持续时间（单位为秒），Transition是滤镜类型，表示想使用哪种特效，取值为0~23。
2cc198a1d5eb0d3eb508d858c9f5cbdb强制页面在当前窗口以独立页面显示，可以防止网页被其他网站框架，编写格式如下：
代码如下:
<meta http-equiv="window-target" content=“_top">
5bdf4c78156c7953567bb5a0aef2fc53页面图标设置，编写格式如下：
代码如下:
<link rel="Shortcut Icon" href="/myicon.ico">
href属性的值是ico图标文件的路径，这里采用的是相对根目录路径
The above is the detailed content of Detailed description of HTML web page header code examples. For more information, please follow other related articles on the PHP Chinese website!