HTML: Building the Structure of Web Pages-HTML Tutorial-php.cn

, and other tags. 2. Provide semantic markers, such as <header>, <nav>, <main>, etc., to improve SEO effect. 3. To realize user interaction through the <form> tag, pay attention to form verification. 4. Use high-level elements such as <canvas> and <video> to combine with JavaScript to achieve dynamic effects. 5. Common errors include unclosed labels and unquoted attribute values, and verification tools are required. 6. Optimization strategies include reducing HTTP requests, compressing HTML, using semantic tags, etc.

introduction

<p> In the vast world of the Internet, HTML (Hypertext Markup Language) is the cornerstone of building web structure. Whether you are a beginner or an experienced developer, understanding the core concepts and best practices of HTML is crucial. This article will take you to explore the mysteries of HTML, from basics to advanced techniques, and help you build more powerful and flexible web pages.

<p> By reading this article, you will learn how to create structured content using HTML, understand how it works in conjunction with CSS and JavaScript, and master some common pitfalls and optimization strategies. Let’s embark on this HTML learning journey together!

Basics of HTML

<p> HTML is the skeleton of a web page, which defines the structure and semantics of content. Each HTML document starts with the tag, containing two main parts: and . The section usually contains metadata and tags linked to external resources, while the section contains user-visible content.

<p> In HTML, tags are the basic units used to mark content. For example, <h1></h1> to <h6></h6> are used for titles, <p></p> are used for paragraphs, <a></a> are used for links, and so on. These tags not only define the structure of the content, but also provide important semantic information for search engines and assistive technologies.

 <!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>My Web Page</title>
</head>
<body>
    <h1 id="Welcome-to-My-Web-Page">Welcome to My Web Page</h1>
    <p>This is a paragraph of text.</p>
    <a href="https://www.example.com">Visit Example.com</a>
</body>
</html>

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The core functions of HTML

Semantic markers

<p> An important feature of HTML is to provide semantic tags, which means you can use specific tags to indicate the meaning of the content, rather than just focusing on its appearance. For example, tags such as <header> , <nav> , <main> , <article> , <section> and <footer> can help you create a more structured and meaningful document.

 <header>
    <h1 id="My-Blog">My Blog</h1>
    <nav>
        <ul>
            <li><a href="#home">Home</a></li>
            <li><a href="#about">About</a></li>
        </ul>
    </nav>
</header>
<main>
    <article>
        <h2 id="My-First-Post">My First Post</h2>
        <p>This is the content of my first post.</p>
    </article>
</main>
<footer>
    <p>&copy; 2023 My Blog</p>
</footer>

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<p> Using semantic tagging can not only improve the readability and maintainability of your code, but also improve the SEO (search engine optimization) effect of web pages, because search engines can better understand your content structure.

Form interaction with users

<p> HTML forms are an important tool for users to interact with web pages. Through the <form> tag, you can create various input fields, such as text boxes, check boxes, radio buttons, and drop-down menus. The form data can be sent to the server through GET or POST methods to realize the function of user submitting information.

 <form action="/submit" method="post">
    <label for="name">Name:</label>
    <input type="text" id="name" name="name" required>
    <br>
    <label for="email">Email:</label>
    <input type="email" id="email" name="email" required>
    <br>
    <input type="submit" value="Submit">
</form>

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<p> When using forms, you need to pay attention to form verification and user experience. HTML5 introduces built-in form verification functions, such as required attributes and pattern attributes, which can be initially validated on the client side, but do not rely on these functions to ensure data integrity and security, server-side verification is still essential.

Example of usage

Basic usage

<p> Let's start with a simple HTML page that shows how to create a structured web page using basic HTML tags.

 <!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>My Simple Page</title>
</head>
<body>
    <h1 id="Welcome-to-My-Simple-Page">Welcome to My Simple Page</h1>
    <p>This is a paragraph of text.</p>
    <ul>
        <li>Item 1</li>
        <li>Item 2</li>
        <li>Item 3</li>
    </ul>
</body>
</html>

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<p> This example shows how to use <h1> , <p> and <ul> tags to create a simple page structure. Each tag has its specific purpose, <h1> is used for the main title, <p> is used for paragraphs, <ul> and <li> are used for unordered lists.

Advanced Usage

<p> In more complex scenarios, you may need to use new HTML5 features such as <canvas> elements to create dynamic graphics, or <video> and <audio> elements to embed multimedia content.

 <canvas id="myCanvas" width="500" height="300"></canvas>

<script>
    var canvas = document.getElementById(&#39;myCanvas&#39;);
    var ctx = canvas.getContext(&#39;2d&#39;);
    ctx.fillStyle = &#39;red&#39;;
    ctx.fillRect(10, 10, 100, 100);
</script>

<video width="320" height="240" controls>
    <source src="movie.mp4" type="video/mp4">
    Your browser does not support the video tag.
</video>

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<p> These advanced usages need to be combined with JavaScript to achieve dynamic effects and interactive functions. When using <canvas> , you can draw complex graphics and animations, while <video> and <audio> elements allow you to play multimedia content directly on the web page.

Common Errors and Debugging Tips

<p> Common errors when writing HTML include unclosed tags, unquoted attribute values, and incorrect nested structures. These errors may cause the web page to display abnormally or fail to pass verification.

 <!-- Error Example: Unclosed Tag-->
<p>This is a paragraph

<!-- Correct Example: Closed Tag-->
<p>This is a paragraph</p>

<!-- Error Example: Property Value is not quoted -->
<input type=text name=username>

<!-- Correct example: quotation marks of attribute values -->
<input type="text" name="username">

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<p> To avoid these errors, it is recommended to use HTML verification tools such as W3C's validators, or modern IDEs and editors, which usually have built-in syntax checking capabilities. In addition, developing good coding habits, such as using indents and comments, can greatly improve the readability and maintainability of the code.

Performance optimization and best practices

<p> In practical applications, optimizing HTML code can significantly improve the loading speed and user experience of web pages. Here are some optimization strategies and best practices:

<ul><li> Reduce HTTP requests : Minimize references to external resources, such as CSS and JavaScript files, can be achieved by merging files or using inline styles and scripts.<li> Compress HTML : Using tools such as Gzip to compress HTML files can reduce file size and speed up transfer speed.<li> Using semantic tags : not only improves SEO effects, but also makes the code easier to understand and maintain.<li> Avoid too much nesting : Too much nesting will increase the depth of the DOM tree, affect the rendering performance, and try to keep the structure simple as possible.<li> Using CDN : For static resources, such as pictures and scripts, the Content Distribution Network (CDN) can be used to speed up loading.

 <!-- Before optimization-->
<link rel="stylesheet" href="styles1.css">
<link rel="stylesheet" href="styles2.css">
<script src="script1.js"></script>
<script src="script2.js"></script>

<!-- After optimization-->
<link rel="stylesheet" href="styles.min.css">
<script src="script.min.js"></script>

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<p> In the optimization process, it is necessary to weigh the advantages and disadvantages of different methods. For example, inline styles and scripts can reduce HTTP requests, but increase the size of HTML files, affecting the first loading speed. Therefore, it is very important to choose the most suitable optimization strategy based on the specific situation.

<p> In short, HTML is the foundation for building modern web pages. Mastering its core concepts and best practices can not only improve your development efficiency, but also provide users with a better experience. I hope this article can provide you with valuable insights and guidance, helping you go further on the learning and application of HTML.

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