Learn how to check if a variable is set in PHP, what its values are, and the differences between the isset, is_null, and empty methods.
Aurelio introduces let and const, two new ES6 keywords for defining variables, showing examples of how they work and how they differ from the var keyword.
Kyle Pennell explains why the two new ES6 variable keywords, const and let, are helpful in giving block scoping.
Variables allow you to use data over and over again throughout your CSS files. In this video I'll teach you about how to use variables in your projects.
Craig takes a look at native CSS variables, which can now be used in Firefox 31. Has the technology become redundant before we can use it?