Iteration in C

Hi there /prog/.

I know Python, and I'm learning C. Both langs have for loops. Python's nicely iterates over a collection of unknown length. C's usually has you specify the length of the collection at compile time, but what if the length is unknown?

My best newbie guess: you terminate the collection with NULL, or you write an iteration function that returns some end-of-collection value when it's done.

>>56
A char array with length stored in element[-1] doesn't have room to specify anything more. The array can be longer, but that length can't be represented.

>>57
I shouldn't need to clarify. A specialized solution when general language was used is not good enough.