Recently for a project I needed to read/write ID3 tags from MP3 files. And after a long search, I found this bloated, monolithic but quite stable library, "getID3".

So, I was looking through the code-base and I found this. This guy literally storing the key value based data embedded as comments within the class file. Then wrote a method to parse the data and even used caching to ensure maximum speed! And such usage is repeated all over the code-base.

So, this is what people used do before arrays were invented :3