Deep understanding of HTML global attributes: 5 important features you will discover

In-depth understanding of HTML global attributes: 5 key features that cannot be missed

HTML global attributes are a set of attributes that apply to almost all HTML elements. They provide a common way to control and customize the behavior and styling of HTML elements. In this post, we'll take a deep dive into 5 key global properties and provide concrete code examples.

1. class attribute: The class attribute is used to specify the style class of one or more elements. By setting the class attribute of multiple elements to the same value, we can easily apply the same style to them. For example, we can create a style class called "highlight" and apply it to multiple elements:

<style>
    .highlight {
        background-color: yellow;
    }
</style>

<p class="highlight">这是一个高亮的段落。</p>
<span class="highlight">这是一个高亮的文本。</span>

In this way, all elements with a class attribute value of "highlight" will have Yellow background color.

2. id attribute: The id attribute is used to specify a unique identifier for a single element. By using the id attribute we can easily select and manipulate specific elements. For example, we can create a button with an id attribute and change its text via JavaScript:

<button id="myButton" onclick="changeText()">点击我</button>

<script>
    function changeText() {
        document.getElementById("myButton").innerHTML = "已点击";
    }
</script>

This way, when the button is clicked, its text will automatically change to "Clicked" .

3. style attribute: The style attribute is used to specify an inline style for a single element. By using the style attribute, we can define its style directly in the HTML element. For example, we can define its font color and size directly in a paragraph element:

<p style="color: blue; font-size: 20px;">这是一个蓝色且字号为20px的段落。</p>

In this way, the style of this paragraph will only apply to that element and will not affect other elements.

4. title attribute: The title attribute is used to provide additional descriptive information for the element. This information will be displayed as a prompt when the user hovers the mouse over the element. For example, we can set the title attribute on an image element to provide a description of the image:

<img src="/static/imghw/default1.png"  data-src="image.jpg"  class="lazy" alt="图片" title="这是一张美丽的图片">

When the user hovers over the image, a tooltip will be displayed containing "This is a beautiful picture" description.

5. data- attribute: The data- attribute is used to store custom data for the element. By using the data-* attributes we can append additional data to HTML elements for use in JavaScript. For example, we can add a custom attribute to a button element to store a specific value:

<button id="myButton" data-value="42" onclick="showValue()">显示值</button>

<script>
    function showValue() {
        var value = document.getElementById("myButton").dataset.value;
        alert("值为：" + value);
    }
</script>

When the button is clicked, a prompt box will pop up showing the value stored in the data-value attribute value.

With a deep understanding of these key HTML global attributes, we can better control and customize our web pages. Whether you're applying styles, selecting elements, manipulating elements, or storing data, these properties provide powerful functionality. In actual development, we should use them flexibly to maximize their effects.

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