Why is a pseudo-class so called?
问题 a:hover Why is it called a "pseudo-class"? Are there any similarities with the concept of "class"? 回答1: In CSS terms, a class is a selector that starts with a full stop, e.g. .foo { ... } It would be used in the form <div class="foo"> This use of "class" is more in the sense "a set or category of things having a common characteristic and differentiated from others by kind or quality", rather than borrowing from OO terminology. A pseudo class is "not quite a real one" as the user agent defines