To begin this series, let's zoom out for a few moments, and review what regular expressions look like, how we can write our own, and what that might look like in our PHP code.

Let's slow down a bit, and focus on a silly example, that will allow us to review such topics as alternation, optional sequences, and non-capturing groups.

Character sets allow us to match any one token, out of a group of characters. As you'll find, this can be incredibly powerful. Let me show you.

Using a practical, real world example, let's review regular expression greediness in this episode.

Often, you'll find yourself in the position of needing to match a set of characters only if they are proceeded or preceded by another sequence. When writing regular expressions, we can use lookaheads and lookbehinds to allow for this.