Anyone know what the purpose of tagging a class with *[class]

问题

I received a file from a client today that is a template for an e-mail and in the css for the mobile version all of the class specifications were preceded with *[class]

e.g.

*[class].centertext {
somespec:0;
}

anyone know what the purpose of adding that to a class is?

thanks.

回答1:

There is a yahoo fix/bug workaround that uses this technique (css classes) in html email design. There was a bug where Yahoo rendered all media queries by default, and this was the common solution.

There have been reports that Yahoo fixed the bug recently.

回答2:

The square brackets are attribute selectors and the '*' is a wild card, so your client is selecting every element that has the class attribute.

来源：https://stackoverflow.com/questions/18877503/anyone-know-what-the-purpose-of-tagging-a-class-with-class