Null, empty, not set, zero, or undefined? The ways that a language expresses and tests for nothing can tall us a lot about how variables are stored and their expected states. We will look at examples from JavaScript, PHP, and MySQL and explore ways to describe nothing. We will discuss some of the common misconceptions with how variables are stored in interpreted languages and identify some best practices for managing memory in our code.

This session is for programmers of any experience level. While some low-level concepts will be introduced, any takeaways can apply to everyday web development work. I hope you leave this session with a better understanding of variables under-the-hood and feel empowered to make small optimizations to your code.