Scenarios suitable for using inline style include: 1. Temporary debugging, such as quickly testing the style of a certain element; 2. Avoid external link CSS in small projects or simple pages; 3. Dynamically generate styles, such as inserting styles when creating nodes by JS. When using it, you need to pay attention to the format: attribute names are named with small camels, and multiple styles are separated by semicolons. Common errors include incorrect naming, missing semicolons and missing units. Compared with class style, inline style is not easy to maintain and reuse, and has higher priority, affecting debugging. It is recommended to use only when using rapid prototyping, email HTML pages, or JS dynamic computing styles to avoid massive abuse to reduce late maintenance costs.

Adding style attributes to HTML elements is the most direct way to set basic styles. Although large-scale use is not recommended in actual development, it is quite convenient in some simple scenarios.

When is it suitable to use inline style?

Inline styles are suitable for temporary debugging, small projects, or dynamically generated style scenarios. For example, if you just want to add a background color to a specific <div> , but don't want to write an extra CSS class, you can quickly see the effect by simply adding <code>style="background: #f0f0f0" at this time.

• Quickly test styles when debugging page layout
• Dynamically insert elements and style (such as JS to create nodes)
• Avoid external links in simple pages or email templates

But note that this method is not conducive to maintenance and reuse, and it is best to use external CSS files in complex projects.

How to use the style attribute correctly?

Pay attention to the format when writing: attribute names are named with small camels, and multiple styles are separated by semicolons. for example:

 <div   style="max-width:90%"></div>

Common error-prone places:

• Incorrectly used a name with horizontal lines, such as font-size written as fontSize (this is only applicable in JS)
• Forgot to add a semicolon, resulting in the subsequent style invalid
• Numerical units are missed, like margin-top: 10 , no px or % is added

In addition, the priority of inline styles is higher than that of ordinary class selectors, which may overwrite the styles you write in CSS files, so be careful when debugging.

What is the difference between class style?

The biggest difference is maintainability and reusability. class can be shared among multiple elements, and can be more flexible in cooperating with media queries, pseudo-classes, etc., while inline style is written on the tag, and can only be modified one by one.

Another difference is that when JavaScript operates styles, the inline styles that are obtained through element.style , not from CSS. So if you use JS to read style.color of an element, it may be an empty string, unless you explicitly wrote the color on the tag before.

Be careful not to abuse

Although it is fast to write, if the entire page is controlled by style , it will be troublesome to maintain later. Especially when multiple elements require the same style, repeating more codes is prone to errors.

It is recommended to use only in the following situations:

• Rapid prototyping
• Mail HTML page (compatibility considerations)
• Insert styles after dynamic calculation of JS

Basically all of this is it. Inline style is not complicated but it is easy to ignore details. It is a tool if it is used well, but it becomes a pit if it is used too much.