What is the new attribute all in css3? What is the use?

For the convenience of web front-end development, CSS3 has added many new attributes (new features). This article will introduce to you what the new attribute all of CSS3 is, so that everyone can understand the role and use of the all attribute. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you. [If you want to learn more about css3 related knowledge, we recommend video learning: css3 tutorial]

First of all, let’s understand what the css3 all attribute is? What can be done?

The all attribute is actually the abbreviation of all CSS attributes, indicating: how all CSS attributes should be; however, the two CSS attributes unicode-bidi and direction are not included. Therefore, we should be able to know the role of the all attribute:

all attribute: You can reset all selected element attributes, except for the two attributes that control the text direction: the direction attribute and the unicode-bidi attribute.

.demo{
  all: unset;
}

Its focus is to allow component-level style reset. Sometimes, setting the desired style from scratch is much easier than making modifications to the original style.

Let’s take a look at the attribute values ​​that can be set by the all attribute:

1. initial: reset the attributes of all selected elements to those defined in the CSS specification initial value.

2. Inherit: The selected element inherits the styles of all its parent elements, including styles that are usually not inheritable.

3. Unset: The selected element inherits any inheritable value passed down from the parent element. If no inheritable value is available, the initial value from the CSS specification will be used for each property.

Note:

Some properties in CSS do not clearly define initial values ​​in the specification, but allow users to set initial values ​​by themselves, such as colors and font families.

all is a shorthand property because it allows us to control the value of each CSS property at once using a single declaration. However, unlike most shorthand properties, there is no practical "longhand" version and no subproperties.

Let’s take a look at the demonstration effect of all:

html code:

<div class="container">
	<div class="parent">
		<div class="alltest">
			<p>Change this div&#39;s <code>all</code> value.</p>
		</div>
	</div>
</div>

css code:

.container {/* 继承 */
  font-family: sans-serif;
  font-size: 1.5em;
  text-align: center;
  text-transform: uppercase;
  text-shadow: 1px 1px 1px black;
}

.parent {
  color: green;/* 继承*/
  
  /* 不继承 */
  background-color: gainsboro;
  width: 80%;
  padding: 1em;
  border: 5px solid #E18728;
}

Rendering (without using the all attribute) :

Then set the .alltest selector and add all attributes respectively:

all:initial;

all:inherit;

all:unset;

Note that when the inherit value is used, the div inherits every property from its parent, including its width, padding and border, which are usually not inherited .

Browser support

The number indicates that the browser supports the functions of this version and above.

PC version

Mobile/tablet version

Summary: That’s it The entire content of this article is hoped to be helpful to everyone's study.

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