When a specific css style is very often used, should it be a own class? [closed]

Question

When I need very often a specific style like float: left is it better to make a own class or put this style in every class where it is needed?

Here is a example page for what I mean.

JS-Fiddle Example

Is it good how the class left is used? Or would it be better when I put every float: left style into the other classes?

Answer 1

The things to consider are readability and repeating yourself.

Readability:

Having a left class with the only rule as float: left will help to make your HTML more readable. Because whenever someone see that class on an element, they know it will be floated left. So in that way it improves readability.

DRY:

With CSS the old adage of "don't repeat yourself" is almost impossible to adhere to, but I think it should still be considered. In this case you should compare. How many times will I add float: left in my CSS? versus How many times will I add class='left' in my HTML?

I would note that most CSS frameworks use utility classes like .left{float:left;}