How to set an Arrays internal pointer to a specific position? PHP/XML

Question

Im trying to build a little site using XML instead of a database.

I would like to build a next and prev button which will work relative to the content I have displa

Answer 1

I use this code for set internal pointer with key of array.

reset($List);
while (key($List) !== $id && key($List) !== null) next($List);
if(key($List) === null) end($List);

After that you can use prev() or next().

Update follow notice from @VaclavSir