There’s not a huge amount to say about Advent of Code day 2. The puzzle is straightforward, but the way I approached the difference between the parts is a little more interesting.

It’s time for Advent of Code again! I’m starting a couple of days late because my laptop got stolen, but the first few days should be easy enough to catch up on.

My first solves are going to be in Ruby, but I hope I’ll have time to come back and try again in some other languages too afterwards.

I’ll upload my progress to my AoC Github repository, but let’s talk about any interesting highlights!

Fun learning about CSS today.

Since HTML5, element IDs can start with numbers. But in the CSS selectors spec, and therefore in document.querySelector, identifiers can’t. So how do you target an element with a numeric ID?