In CSS, there are 4 keywords that can theoretically be applied to any CSS property, they are initial (initial), inherit (inherited), unset (not set), revert (reduction). The value of all can only be the above four keywords. This article will introduce initial, inherit, unset, revert and all.
initial
Represents the initial default value of the element attribute (the default value is defined by the official CSS specification)
Compatibility: IE does not support
[Note] The initial default values of each attribute are moved here
//display在官方CSS规范中定义的默认值是inline
Copy after login
##inherit
means The calculated value of the corresponding attribute of the element's immediate parent element
Compatibility: IE7-Not supported
unset
unset is relatively more complicated than initial and inherit. Indicates that if the property is inheritable by default, the value is inherit; otherwise, the value is initial. In fact, setting unset is equivalent to not setting
Compatibility: IE does not support it, safari9- does not support it, ios9.2- does not support it, android4.4.4- does not support it
【Commonly used default is available Inherited style】
color cursor direction font letter-spacing line-height list-style text-align text-indent text-shadow text-transform white-space word-break word-spacing word-wrap writing-mode
Copy after login
//内容为测试一的元素和内容为测试二的元素的样式是一样的
Copy after login
revert
represents the default value of the element attribute defined in the style sheet. If explicitly set in the user-defined style sheet, follow this setting; otherwise, follow the style setting in the browser-defined style sheet; otherwise, it is equivalent to unset
Compatibility: only safari9.1 and ios9. 3 Support
all
means to reset the attribute values of all CSS attributes except unicode-bidi and direction. The values can only be initial, inherit, and unset. Compatibility with revert
: IE not supported, safari9-not supported, ios9.2-not supported, android4.4-not supported
[1]When all:initial,. All attributes of in take the default value
border:none;padding:0;color:black;
Copy after login
[2]When all:inherit, all attributes of .in take the inherited value of the parent element
border:1px solid black;padding:20px;color:red;
Copy after login
[3]When all:unset , all attributes of .in are equivalent to not setting a value, the default is inheritable inheritance, the non-inheritable ones keep the default value
border:none;padding:0;color:red;
Copy after login
This article is reproduced from: https://www.cnblogs.com/xiaohuochai/p/5464456.html
Recommended learning:
css quick start
The above is the detailed content of Understand the keywords initial, inherit, unset, revert and all attributes in CSS. For more information, please follow other related articles on the PHP Chinese website!