html中class的作用是什么
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在html中,class规定元素的类名,语法格式为“<元素名称 class="value">”。class属性大多数时候用于指向样式表中的类(class)。不过,也可以利用它通过JavaScript来改变带有指定class的HTML元素。
class 属性规定元素的类名(classname)。
class 属性大多数时候用于指向样式表中的类(class)。不过,也可以利用它通过 JavaScript 来改变带有指定 class 的 HTML 元素。
提示和注释
注释:class 属性不能在以下 HTML 元素中使用:base, head, html, meta, param, script, style 以及 title。
提示:可以给 HTML 元素赋予多个 class,例如:
提示:类名不能以数字开头!只有 Internet Explorer 支持这种做法。
语法
实例:
Header 1
A paragraph.
请注意这个重要的段落。:)
效果:

扩展资料:
id属性
id 属性规定 HTML 元素的唯一的 id。
id 在 HTML 文档中必须是唯一的。
id 属性可用作链接锚(link anchor),通过 JavaScript(HTML DOM)或通过 CSS 为带有指定 id 的元素改变或添加样式。
HTML 4.01 与 HTML5之间的差异
在 HTML5 中, id 属性可用于任何的 HTML 元素 (它会验证任何HTML元素。但不一定是有用)。
在 HTML 4.01 中, id 属性不能用于: ,
, ,
,
,
基本
文件
流程
错误
SQL
调试
- 请求信息 : 2026-05-21 01:59:41 HTTP/1.1 GET : /article/gdedop.html
- 运行时间 : 1.0377s ( Load:0.0023s Init:0.3783s Exec:0.6458s Template:0.0113s )
- 吞吐率 : 0.96req/s
- 内存开销 : 468.23 kb
- 查询信息 : 12 queries 5 writes
- 文件加载 : 36
- 缓存信息 : 0 gets 0 writes
- 配置加载 : 130
- 会话信息 : SESSION_ID=63apq9jhpppesshcltkpj3q3h1
- /home/wwwroot/bluegullmedia/wwwroot/index.php ( 1.09 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/ThinkPHP.php ( 4.61 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Think.class.php ( 12.26 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Storage.class.php ( 1.37 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Storage/Driver/File.class.php ( 3.52 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Mode/common.php ( 2.82 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Common/functions.php ( 53.56 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Hook.class.php ( 4.01 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/App.class.php ( 13.49 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Dispatcher.class.php ( 14.79 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Route.class.php ( 13.36 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Controller.class.php ( 11.23 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/View.class.php ( 7.59 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Behavior/BuildLiteBehavior.class.php ( 3.68 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Behavior/ParseTemplateBehavior.class.php ( 3.88 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Behavior/ContentReplaceBehavior.class.php ( 1.91 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Conf/convention.php ( 11.15 KB )
- /home/wwwroot/bluegullmedia/wwwroot/App/Common/Conf/config.php ( 2.16 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Lang/zh-cn.php ( 2.55 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Conf/debug.php ( 1.49 KB )
- /home/wwwroot/bluegullmedia/wwwroot/App/Home/Conf/config.php ( 0.31 KB )
- /home/wwwroot/bluegullmedia/wwwroot/App/Home/Common/function.php ( 3.33 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Behavior/ReadHtmlCacheBehavior.class.php ( 5.62 KB )
- /home/wwwroot/bluegullmedia/wwwroot/App/Home/Controller/ArticleController.class.php ( 6.02 KB )
- /home/wwwroot/bluegullmedia/wwwroot/App/Home/Controller/CommController.class.php ( 1.60 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Model.class.php ( 60.11 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Db.class.php ( 32.43 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Db/Driver/Pdo.class.php ( 16.74 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Cache.class.php ( 3.83 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Cache/Driver/File.class.php ( 5.87 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Template.class.php ( 28.16 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Template/TagLib/Cx.class.php ( 22.40 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Template/TagLib.class.php ( 9.16 KB )
- /home/wwwroot/bluegullmedia/wwwroot/App/Runtime/Cache/Home/7540f392f42b28b481b30614275e4e55.php ( 18.20 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Behavior/WriteHtmlCacheBehavior.class.php ( 0.97 KB )
- /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Behavior/ShowPageTraceBehavior.class.php ( 5.24 KB )
- [ app_init ] --START--
- Run Behavior\BuildLiteBehavior [ RunTime:0.000015s ]
- [ app_init ] --END-- [ RunTime:0.000069s ]
- [ app_begin ] --START--
- Run Behavior\ReadHtmlCacheBehavior [ RunTime:0.000104s ]
- [ app_begin ] --END-- [ RunTime:0.000150s ]
- [ view_parse ] --START--
- [ template_filter ] --START--
- Run Behavior\ContentReplaceBehavior [ RunTime:0.000152s ]
- [ template_filter ] --END-- [ RunTime:0.000230s ]
- Run Behavior\ParseTemplateBehavior [ RunTime:0.010218s ]
- [ view_parse ] --END-- [ RunTime:0.010276s ]
- [ view_filter ] --START--
- Run Behavior\WriteHtmlCacheBehavior [ RunTime:0.000113s ]
- [ view_filter ] --END-- [ RunTime:0.000145s ]
- [ app_end ] --START--
- 1064:You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') LIMIT 1' at line 1
[ SQL语句 ] : SELECT `id`,`pid`,`navname` FROM `cx_nav` WHERE ( id= ) LIMIT 1
- 1064:You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') LIMIT 1' at line 1
[ SQL语句 ] : SELECT `id`,`navname` FROM `cx_nav` WHERE ( id= ) LIMIT 1
- 1064:You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1
[ SQL语句 ] : SELECT `id`,`navname` FROM `cx_nav` WHERE ( pid= )
- [8] Undefined index: pid /home/wwwroot/bluegullmedia/wwwroot/App/Home/Controller/ArticleController.class.php 第 47 行.
- [2] mkdir(): Permission denied /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Cache/Driver/File.class.php 第 59 行.
- [2] mkdir(): Permission denied /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Cache/Driver/File.class.php 第 59 行.
- [8] Undefined index: db_host /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Db.class.php 第 120 行.
- [8] Undefined index: db_port /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Db.class.php 第 121 行.
- [8] Undefined index: db_name /home/wwwroot/bluegullmedia/wwwroot/ThinkPHP/Library/Think/Db.class.php 第 122 行.

1.0377s
