It is not known is the one programming language, because CSS does not include the basic characteristics of the programming language, such as variables, data types, flow control statements and so on. Such developers writing distal CSS code, the code can only code line by line, and such low CSS code reuse, the disposable substantially the same to its low maintenance and low expansibility. So, Sass came into being. Sass CSS as an extension language, which allows developers to use front-end programming ideas to write CSS code, which greatly improves the efficiency of front-end coding, reuse, maintenance and other issues. So in this chapter, we will explain in detail its basic grammar and use of Sass.
Sass appear before, CSS is basically a designer's tool, not the developer tools. In the eyes of developers, CSS is a very troublesome thing, it has no variables, no conditional statements, but simple line by line description, quite cumbersome to write.
What is Sass
Open Sass (sass-lang.com) official website, we can see the answer to the title. As shown in Figure 1:
Figure 1 Sass official website
It can be seen wafting English official website impressively line of characters "have CSS super capacity"; then we look at its subtitle, not humble to tell all visitors "Sass is the world's most mature, the most stable, most professional level CSS extension language. " This high degree of self-evaluation rare in the industry, this high degree of confidence that only those with the real strength of the application software will have, but these evaluations for Sass is pretty fair. why? From a historical perspective, Sass was born in 2007, lasted nine years of exploration, grinding, repair, after innovation, Sass gradually to cater to the trend, reducing the learning curve, so that the majority of developers is simple to learn, easy to to get started while in function also showed their superior, powerful side, this behind us examples you will appreciate its power.
Sass essence, is an independent programming language, which has an associated programming syntax, but is fully compatible with CSS syntax, just outside the CSS syntax, added some programming features, such as variables, data types, function, mixed macros, flow control statements and so on. We use Sass to write programming code will eventually compiled CSS file, because in the end only know CSS file browser.
It features one sentence: we write the code Sass finally produced after compiling a CSS file.