How the game remembers

Close the game, come back later, and your run is still there. How does a web page remember things after you leave? And why does this game go out of its way to be careful about what it writes down? Two good questions with instructive answers.

Concept: "persistence" / saving. By default, a web page forgets everything the moment you close the tab. To remember, it has to deliberately write information somewhere lasting. Browsers give pages a little storage box for exactly this, called localStorage — a small notebook the page can jot notes in and read back later.

This game keeps four separate notes in that box:

Saving carefully: don't write down everything

You might think saving is just "write down the whole game." But some of what the game holds in memory is temporary junk — half-finished screen animations, and pieces that can't be safely written down at all. So before saving, the game strips those out:

2214  function serializeSave(s) {
2215    var o = {};
2216    Object.keys(s).forEach(function (k) { if (SAVE_DROP.indexOf(k) === -1) o[k] = s[k]; });
2217    o.view = "lot";
2218    return o;
2219  }
2220  function saveGame(s) {

Concept: "serializing." To save something, a program has to turn it into plain text it can write down and read back — that's serializing. The catch: some things (like live animations or functions) can't be turned into plain text. So the game carefully saves only the parts that can, and rebuilds the rest when you return.

The game is also picky about when it saves: only when you're back at the parking lot between shows — never in the middle of a drive or an event. That guarantees every save is taken at a clean, safe moment.

Loading: rebuild what wasn't saved

When you return and load, the game puts back everything it saved, then recalculates the things it deliberately didn't save — including your fuel and food limits (the "derived values" gotcha from the economy chapter). It also double-checks the saved data looks valid before trusting it, so a corrupted save is ignored rather than crashing the game.

Concept: never trust stored data blindly. Saved files can be old, incomplete, or tampered with. Careful programs check that loaded data makes sense before using it. This one confirms your save has a character and a valid position before loading it.