In HTML and CSS, elements can be classified as inline elements, block-level elements, and empty (void) elements. These elements have different characteristics and purposes, and play an important role in web development. So today, we will discuss in depth the characteristics and usage of these elements.
1. Inline elements
Inline elements are elements that do not cause a new paragraph to start. These elements usually only take up the width they need, not the entire line like block-level elements. Some common HTML inline elements include <a>、<span>、<strong>、<em>etc. Their characteristics are as follows:
- The width is determined by the content and will not occupy a single line.
- Height is determined by font size, height and width cannot be set.
- Can only contain other inline elements and some specific elements, such as
<a>,<img>,<br>etc.
Inline elements are usually used to apply CSS styles, which can set font style, text color, font size, text shadow, etc. Visually, inline elements are adjacent to the surrounding text and are suitable for embedding text or creating navigation links, etc.
2. Block-level elements
A block-level element is an element that causes a new paragraph to begin. These elements usually take up the entire available width and automatically create new lines before and after them. Some common HTML block-level elements include <p>、<div>、<h1>etc. Their characteristics are as follows:
- Width defaults to 100%.
- The height can be set, and the width and height can be changed at will.
- Can contain any type of element, including inline and block-level elements.
Block-level elements are often used for layout and building page structure. For example, you can use <div>elements to create different areas of a page, and <p>elements to separate different paragraphs. Block-level elements are also suitable for responsive design according to viewport width, including creating navbars, sidebars, page headers, bottoms, etc.
3. Empty elements
Empty elements, also known as Void elements, refer to elements that have no content or child elements. In HTML/XML, these elements have no closing tags and can be defined using a simple syntax. Some common HTML empty elements include <img>、<br>、<hr>etc.
- Empty elements take up no page layout space.
- Empty elements have a very specific purpose and meaning.
- Empty elements are often used to insert pictures, create horizontal lines, enter line breaks, etc.
Summarize
In HTML and CSS, elements can be categorized as inline elements, block-level elements, and empty elements. Each element has different characteristics and uses, and can be used for different needs, so as to realize rich and colorful web page design. Developers should master the characteristics and usage methods of these common elements in order to better apply them to optimize the design of Web pages.