To define the minimum height problem for an inline element span

Span this label, presumably everyone is familiar with it, but it is very difficult to use, especially when you need to define the width and height of the time

Making HTML pages often uses the tag of span, but some friends don't use the tag very well, and seem to think it's good, but it's a hassle to use, especially when it comes to defining width and height.
once a friend asked: Why to use CSS to define the height and width of the span, its width and height has not changed, as if the same failure?

In fact, the problem is simple-to recognize the properties of span, because span is an inline element, and inline elements are ignored width and height, understand this solution is very simple, the solution is to use CSS to make span into a boxed element.

There are two ways to define an inline element as a boxed element:

1. Use Display properties directly to define it as a boxed element;
Display:block;

2. Use float property float to automatically define it as a boxed element;
Float:left;