Can you give me a quick runthrough of what these 4 keywords are used for and why?
I understand the basics that google would tell you on register and volatile, but would like to know a little more (just a practical overview). Extern and explicit confuse me a little as I've never found a reason to have to use them myself despite doing fairly low-level embedded systems code. Again, I can google but I'd prefer a quick, practical summary from an expert so it sticks in my mind.