Best Practice – Code and formatting

CSS

Hypens, lower case, example: .btn-green or #sidebar-right

JS

Variable and function names should be full words, using camel case with a lowercase first letter. 

Example: camelCase

PHP

Use lowercase letters in variable, action/filter, and function names (never camelCase). Separate words via underscores. Don’t abbreviate variable names unnecessarily; let the code be unambiguous and self-documenting.

<?php
function some_name( $some_variable ) {}