The encoding setting of an HTML document

HTML document encoding settings are crucial for content display and browser parsing. The document type declaration and meta tags are fundamental configurations. UTF-8 is the recommended multilingual encoding format. The meta charset must be placed in the early part of the head section. HTTP header encoding takes precedence over document declarations. Special characters need to be escaped using HTML entities. Multilingual documents require attention to CJK character handling. Encoding issues can be diagnosed using developer tools. Legacy systems need compatibility with traditional encoding formats. Modern front-end tools like webpack and Vue allow encoding configuration. JavaScript string operations require attention to encoding conversion. Mobile platforms like WeChat browsers need special handling for encoding settings. Proper encoding settings effectively prevent garbled text and layout issues.

Radio button (input type="radio")

Radio buttons are HTML form elements used for single selection, implemented via the `input` tag with the `radio` type. Paired with the `label` tag, they improve accessibility. Key attributes include `name` for grouping, `value` for submission, `checked` for default selection, and `disabled` to deactivate an option. Grouping relies entirely on the `name` attribute, regardless of position. Always use the `label` tag for association, which can be done implicitly or explicitly. CSS allows custom styling by hiding the native button and creating new styles with pseudo-elements. JavaScript can dynamically control states, listen for changes, and retrieve values. Upon form submission, only the selected value is sent; unselected options are omitted. Modern frameworks like React and Vue integrate radio buttons with state management. HTML5's `required` attribute enables basic validation. Advanced applications include CSS-only tabs, image selectors, and responsive menus.

Password input box (input type="password")

The password input field is an HTML form element designed for securely entering sensitive information, implemented using `input type="password"`. User input is displayed as dots or asterisks to prevent visual exposure. Core attributes include `name` and `id` for form submission and label association, `placeholder` for input hints, `required` to enforce input, and `minlength` and `maxlength` to restrict length. Modern applications often feature a "show password" button, toggling input types via JavaScript, and password strength validation for real-time feedback. Security best practices include disabling autofill to prevent password manager capture and emphasizing the importance of server-side validation. CSS allows for custom styling, while mobile optimization prevents keyboard auto-correction. Accessibility must ensure compatibility with assistive technologies. Advanced features include password generator integration and policy hints, with attention to browser compatibility and performance. Popular frameworks like React and Vue offer dedicated implementations. Finally, regular security audits are crucial to ensure secure password transmission and storage.

Text input box (input type="text")

The HTML text input field is created using the `input` tag with the `type="text"` attribute, defining a basic form element that allows users to enter single-line text. It covers commonly used attributes such as `value` and `placeholder`, as well as CSS styling, data validation, and JavaScript interaction methods. Advanced features include autocomplete, input masking, accessibility considerations, responsive design techniques, implementation in mainstream frameworks, performance optimization, and security precautions. Practical application scenarios, browser compatibility, and future trends—such as intelligent prediction, voice input, and other developmental directions—are also discussed.

Table caption

The HTML table caption (`<caption>`) is an important element that describes the table's content. It is directly nested inside the `<table>` tag, typically as the first child element. The basic syntax is simple, and its style can be controlled via CSS, such as using the `caption-side` property to adjust its position—defaulting to the top but can be changed to the bottom. It is particularly important for screen reader users and should be kept concise and descriptive, avoiding redundant words. For complex tables, multi-level headings can be combined with other elements. Unlike `<figure>` and `<figcaption>`, the `<caption>` is exclusive to tables, providing clearer semantics. In responsive design, its display can be adjusted. Practical applications include e-commerce product comparison tables. JavaScript can dynamically generate its content, and for multilingual websites, internationalization must be considered. The `caption-side` property has good browser compatibility, supported by most mainstream browsers. For older browsers, alternative CSS methods can simulate the effect.

Cell spacing and margins

In HTML tables, the cellspacing and cellpadding attributes are two key properties that control table layout. Cellspacing defines the blank space between cells, affecting the overall dimensions of the table, while cellpadding controls the inner padding between content and borders. Modern development recommends using CSS's border-spacing and padding to replace these HTML attributes. Border-spacing allows separate horizontal and vertical spacing settings, but spacing is ignored when border-collapse is applied. In practice, responsive design adjustments are necessary for spacing on mobile devices. Note the spacing overlap issue in nested tables, as background colors will appear in the spacing area. Form elements require special handling for spacing, and print styles should minimize spacing to save space. JavaScript can dynamically modify spacing, while CSS Grid Layout's gap property offers similar functionality. Proper spacing is crucial for readability and accessibility, and WCAG guidelines should be followed to ensure a good user experience.

The width and height of the table

The width and height of HTML tables can be flexibly adjusted through CSS or HTML attributes. Table width has two forms: fixed pixels and percentages. Fixed width is suitable for precise control, while percentages are used for responsive layouts. The CSS `width` property takes precedence over HTML attributes, and using CSS is recommended. Table height is usually automatically determined by content but can also be explicitly set, with row height control being more common. On mobile devices, tables require special handling, such as using `max-width` to prevent overflow. Cell width can be defined via `colgroup`. The `table-layout` property affects width calculation: fixed layout ensures precise control, while automatic layout is the default. Nested tables require attention to width inheritance. Borders increase the actual occupied space. Fixed headers with scrollable content areas can be combined with Flexbox or Grid. For print styles, ensure the table displays completely.

The border settings of the table

Table borders are visual elements in HTML tables that separate cells and define the table structure. Borders can be set using HTML attributes or CSS, with CSS offering more powerful control over border width, style, and color. There are various border styles, such as solid, dotted, and dashed. The `border-collapse` property determines whether borders are separated or merged. Different borders can be set for different edges, and `box-shadow` can be used to add shadow effects. Responsive design must account for mobile device displays. Advanced techniques include zebra striping, hover effects, and border animations. Performance, browser compatibility, accessibility, and print styles must also be considered. Borders relate to table layout, backgrounds, pseudo-elements, and JavaScript interactions. Special attention is needed for scenarios like cell merging, table scrolling, sort indicators, pagination, exporting, dark mode, etc. CSS frameworks, CSS variables, nested tables, rounded corners, header groups, filtering, editing, drag-and-drop, and other advanced applications also require specific handling of border styles.

The basic structure of a table (table, tr, td)

HTML tables are defined by the table element, which contains rows (tr) and cells (td) to display row and column data. The table element serves as the container for the table and can include tr, th, td, and other elements. Common attributes include border, width, cellspacing, and cellpadding. The tr element defines a table row and contains td or th elements, with alignment and background color settings available. The td element defines a standard cell and can span rows or columns. The th element defines a header cell, which is bold and centered by default. Tables can be divided into thead, tbody, and tfoot sections. Complex tables can use colspan and rowspan to merge cells. To enhance accessibility, use th and scope attributes, and provide a caption for the title. Responsive design can be achieved with CSS for horizontal scrolling. CSS offers better control over table appearance. JavaScript enables dynamic operations like adding/deleting rows, sorting, and pagination. Table sorting is implemented by comparing cell content, while pagination controls display by calculating row counts and page numbers.

Methods for embedding Flash

Traditional methods for embedding Flash content in web pages include using a combination of `<object>` and `<embed>` tags to ensure browser compatibility. The SWFObject library offers a more concise API and better compatibility. Another approach is dynamically creating Flash content via JavaScript. Modern browsers have gradually phased out Flash support, requiring fallback content. HTML5 standardized the `<embed>` tag, while `<iframe>` can isolate Flash content. FlashVars allows passing parameters to Flash. Detecting Flash installation is crucial. Responsive design ensures Flash adapts to different screens. Express Install enables automatic updates. Fullscreen mode requires special configuration, and cross-domain communication needs security settings. Adobe provides official detection tools. These methods help maintain Flash content in legacy systems.