Check out example codes for "scss mixin skip argument use default". It will help you in understanding the concepts better.

Code Example 1

// Since SASS 3.1 you can pass named arguments and omit the arguments you do not need
@include linear-gradient($from: #7a7a7a, $to: #1a1a1a, $ie-filters: true);

Learn ReactJs, React Native from akashmittal.com