> After reading through this, I'm not sure if it's a list of jokes or real information?

The whole point is pulling peoples legs, the joke being on the person who doesn't know the language well enough and takes it serious.

The answers in the list are the equivalent of telling an apprentice to go get a can of blinker fluid (or Siemens Lufthacken, etc...), which they dutifully do and end up getting laughed at.

E.g. just before the one you quoted was this gem:

> 1.8: What's the auto keyword good for?

>

> Declaring vehicles.

Regarding your question:

> How is this a good example of hexadecimal input?

It isn't. In C, a leading zero in an integer literal means octal. It compiles and works out, because `7`, `07` and `0x07` happen to have the same value.