How to use H5 and JS in web pages?

H5 and JS collaborate to create cool web pages: H5 defines structures and elements, JS gives dynamics and interactions; JS operates H5 elements through DOM; and cooperates with technologies such as AJAX, frameworks and animations to achieve complex effects; pay attention to JS execution efficiency to ensure code optimization and readability.

How to work together between H5 and JS to create cool web pages? This question is well asked! It is not a simple "addition, subtraction, multiplication and division", but an art, an art that requires skills and experience.

Many novices will think that H5 is the skeleton of the web page, and JS is flesh and blood. This is true, but it is too superficial. H5, also known as HTML5, defines the structure, content, and some basic interactive elements of the web page. But to make the web page move and truly live, JS, that is, JavaScript, is the soul. It gives web page dynamic effects, responds to user interaction, processes data, and implements complex logic. Only by combining the two can we create a truly amazing web experience.

Let’s talk about the basics first. You have to understand the H5 tag system, such as <div> , <code><span></span> , <img src="/static/imghwm/default1.png" data-src="image1.jpg" class="lazy" alt="How to use H5 and JS in web pages?" > , <video></video> , etc., these are objects of JS operation. JS accesses and modifys these H5 elements through DOM (document object model). Imagine H5 building a house, and JS lays out furniture and installs electrical appliances to make the house comfortable and livable.

Take a look at it, you want to do a simple picture carousel. H5 is responsible for providing the image container and the image itself, which may be several <img src="/static/imghwm/default1.png" data-src="image1.jpg" class="lazy" alt="How to use H5 and JS in web pages?" > tags, or a <div> container, containing multiple images. JS is responsible for controlling the display and switching of pictures, such as setting a timer, automatically switching pictures based on time, or manually switching pictures in response to user click events.<p> Code example, some useful information:</p> <pre class="brush:php;toolbar:false"> &lt;code class=&quot;html&quot;&gt; &lt;title&gt;图片轮播&lt;/title&gt; &lt;style&gt; .slider { width: 300px; height: 200px; overflow: hidden; } .slider img { width: 300px; height: 200px; } &lt;/style&gt; &lt;div class=&quot;slider&quot;&gt; &lt;img src=&quot;/static/imghwm/default1.png&quot; data-src=&quot;image1.jpg&quot; class=&quot;lazy&quot; alt=&quot;Image 1&quot;&gt; &lt;img src=&quot;/static/imghwm/default1.png&quot; data-src=&quot;image2.jpg&quot; class=&quot;lazy&quot; alt=&quot;Image 2&quot;&gt; &lt;img src=&quot;/static/imghwm/default1.png&quot; data-src=&quot;image3.jpg&quot; class=&quot;lazy&quot; alt=&quot;Image 3&quot;&gt; &lt;/div&gt; &lt;script&gt; const slider = document.querySelector(&amp;#39;.slider&amp;#39;); const images = slider.querySelectorAll(&amp;#39;img&amp;#39;); let currentImage = 0; setInterval(() =&gt; { images[currentImage].style.display = &amp;#39;none&amp;#39;; currentImage = (currentImage 1) % images.length; images[currentImage].style.display = &amp;#39;block&amp;#39;; }, 3000); // 每3秒切换一次&lt;/script&gt; &lt;/code&gt;</pre> <p> This code is simple, but it shows the combination of H5 and JS. H5 is responsible for building the carousel structure, and JS is responsible for controlling the switching of pictures.</p> <p> Of course, this is just the simplest example. In practical applications, you will use more advanced techniques, such as AJAX asynchronous loading of data, using various JS frameworks or libraries (such as React, Vue, Angular) to simplify development, handle complex animation effects, etc.</p> <p> There is a pit here that many novices are prone to ignore: JS execution efficiency. If your JS code is badly written, full of redundant calculations and inefficient DOM operations, your web page will be stuttered and the user experience is extremely poor. Therefore, when learning JS, you must not only learn grammar, but also learn to optimize and write efficient code. Remember, the readability and maintainability of the code are also very important. Don’t write difficult code to pursue the so-called "efficiency".</p> <p> In short, the cooperation between H5 and JS requires you to have a deep understanding of both. It is not only a pile of code, but also an overall grasp of web design and user experience. Only by practicing and thinking more can you truly master this art. Don’t forget that only by constantly learning new technologies and methods can we go further on the road of front-end development.</p> </div>