Arrays and Pointers
- Arrays in C are just like arrays in ASM. They're a contigous sequence of
memory starting at some address.
- Array variables store the address of the start of the array.
- C knows how big the type stored in array is.
- For arrays in ASM, we had to manually calculate the byte offsets.
- An array of words in C would be xs, xs, etc.
- Pointers are variables that store memory addresses with an associated type
so "int*" (int pointer) is the address of an int.
- C lets you do arthmetic with pointers.
- If you add one to an int pointer, it steps to the next int-sized chunk of memory.
So if p is a pointer to a 4 byte int, then (p + 1) is the address increased by
- Show sizeof: char, short, int, long, float, double, char*, long*
- Array varibles and pointers are the same thing with different notation.
- If pp is a pointer and aa is an array, both of the same type pointing to the same
address, then pp and *(pp + 3) are the same thing.
- Strangely, pp[ii] and ii[pp] are the same thing too.