What Is Hairball?

Hairballs are no fun. You know what they are: those fuzzy, tangled clumps of hair you find in your shower drain or on your shower floor. They're gross and make you feel like you're living in a horror movie. If you have one in your shower, you probably have to call a plumber to get it out (and they probably charge extra for that). Here's the thing: hairballs are also a metaphor for code. In IT, pros use the term "hairball" to refer to any jumbled, confusing, inefficient or unnecessarily large piece of code or some other tangled mess. When applied to code, "hairball" implies several things: lack of utility, lack of user-friendly design, and often a lack of readability by other software engineers who might be trying to modify it later on down the line. Hairballs are a common problem for cats. They eat, and then they get hair caught in their stomachs. That's where the name comes from. But programmers have our version of hairballs: poorly written code. Hairball code is a little bit like that—it just doesn't work well, and it gets stuck in your computer and makes everything slow down or even crash. So let's talk about avoiding making your code into a hairball! Hairballs can happen when there are too many comments in your code or when the words aren't helpful (they're just there to make things look pretty). They can also happen when you use too many operators or commands to do a job that could be done more efficiently with fewer elements. Maybe worst of all, hairballs can happen when there are circular references in your designs—where one piece of code refers back to another part of code that hasn't been written yet!