Since Sass version 3.3.1., you can not only use the @mixin
directive, but also the @function
directive. Pure Sass functions created with the @function
directive do not generate output in the compiled CSS code, but return a single value. In this recipe, you will create a Sass function that converts value in px
(pixel) units to values in em
units.
Read the Installing Sass for command line usage recipe of Chapter 1, Getting Started with Sass, and install Ruby Sass on your system. In the Using Sass interactive mode and SassScript recipe of Chapter 1, Getting Started with Sass, you can read how to use the interactive Sass mode. Operations with units, as used in this recipe, can easily be tested in the interactive Sass mode.