Garbage Collection is the process of cleaning up a computer’s memory by getting rid of data that’s no longer needed by a program. There are several algorithms for doing this. (Black squares represent free memory.)

Here’s a “reference counter” garbage collector:


Here’s a “mark sweep” garbage collector:


Here’s a “copy” garbage collector:


And here’s what happens if you don’t bother with garbage collection until you’re done:


You can read all about these here (5 minute read)

Here are three links worth your time:

  1. Net Neutrality, Walled Gardens, and the future of the the Open Internet (24 minute read)
  2. What are the SOLID principles, and how do they make your code cleaner? (12 minute watch)
  3. 12 free things you can do to jump-start your UX Design career (9 minute read)

Thought of the day:

“Securing a computer system has traditionally been a battle of wits: the penetrator tries to find the holes, and the designer tries to close them.” — Gosser

Funny of the day:


Webcomic by CommitStrip.

Study group of the day:

freeCodeCamp Washington, D.C.


Happy coding!

– Quincy Larson, teacher at freeCodeCamp