Usage of id in html

ID is used in HTML to provide a unique identifier for an element. Its uses include: Applying CSS styles JavaScript actions Creating anchor links Best practices are to remain unique, use descriptive names, avoid spaces, and use lowercase letters.

Usage of ID in HTML

ID is an important attribute in HTML and is used to provide content in the page. Provides a unique identifier for a specific element.

Definition

The value of the ID attribute must be a string, and the ID value must be unique for each element in the page. The ID value should start with a letter or underscore and can be followed by any number of letters, numbers, or underscores.

Uses

The ID attribute has the following main uses:

• CSS style: You can use the ID attribute Apply unique CSS styles to specific elements to control their appearance and behavior. For example:

<code class="css">#my-element {
  color: red;
  font-size: 20px;
}</code>

• JavaScript Actions: Through the ID attribute, JavaScript can get, modify, and manipulate a specific element and its content. For example:

<code class="javascript">const element = document.getElementById("my-element");
element.style.display = "none";</code>

• Anchor link: The ID attribute can be used to create an anchor link, making a specific location on the page directly accessible through the link. For example:

<code class="html"><a href="#my-section">前往我的部分</a></code>

Best Practices

The following best practices should be followed when using the ID attribute:

• Maintain uniqueness: Ensure that the ID value of each element in the page is unique.
• Use descriptive names: Choose meaningful ID names that reflect the purpose or content of the element.
• Avoid using spaces: Avoid using spaces in ID values.
• Use lowercase letters: Although HTML IDs are not case-sensitive, it is recommended to use lowercase letters for consistency.

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