Master the core points of HTML global attributes: 5 key knowledge points to remember

The core points of mastering the global attributes of HTML: 5 key knowledge points to remember

HTML is the basic language for building web pages, and global attributes can be applied in HTML properties of any element. Understanding and mastering these global properties is critical to writing efficient and flexible web pages. This article will introduce 5 key knowledge points and provide specific code examples.

1. class attribute: The class attribute is used to define one or more class names for HTML elements, so that we can control the style or behavior of specific class names through CSS or JavaScript. The following is an example:

<div class="box red">这是一个红色的方框</div>
<div class="box green">这是一个绿色的方框</div>

In the above code, we added the class attribute to the two <div> elements, respectively <code>box red and box green, we can use CSS to control the styles of these two class names differently.

2. id attribute: The id attribute is used to define a unique identifier for an HTML element. Unlike the class attribute, the id attribute can only exist uniquely in the same HTML document. Here is an example:

<div id="header">这是网页的头部内容</div>

In the above code, we have added the id attribute to the <div> element with the value <code>header. Through the id attribute, we can easily select and operate specific elements in CSS or JavaScript.

3. style attribute: The style attribute is used to directly specify inline styles for HTML elements. Inline styles will override rules of the same name in external or internal style sheets. The following is an example:

<div style="color: red; font-size: 14px;">这段文字是红色的，字体大小为14像素</div>

In the above code, we use the style attribute to directly specify the font color and size. Although inline styles are convenient, they are best used only in specific situations and try to use external style sheets for style management.

4. title attribute: The title attribute is used to add an additional prompt information to an HTML element, usually displayed when the mouse is hovered over the element. Here is an example:

<a href="https://example.com" title="点击访问示例网站">示例网站</a>

In the above code, we added the title attribute to the <a></a> element. When the mouse is hovering over the link, the browser A prompt box will be displayed saying "Click to visit the sample website".

5. data-Attribute: data- attribute is used to store custom data. It can be named arbitrarily, starting with "data-". This custom data can be easily accessed and manipulated in JavaScript. The following is an example:

<button data-color="red">红色</button>
<button data-color="green">绿色</button>

In the above code, we added data-* attributes to the two button elements, which are "data-color". In JavaScript, we can obtain these custom data through methods such as getElementByTagName and process them accordingly.

By learning and practicing these 5 key global attribute knowledge points, we can better grasp the flexibility and functionality of HTML. These attributes are widely used in web development, and a deep understanding of them will allow us to write better web pages.

The above are the core points of mastering the global attributes of HTML. I hope it will be helpful to your study. work hard together!