Why assign a pointer to an array?

[bbugyi200]

Why would you ever assign a pointer to an existing array?

Take this link for example. Why would you ever do this?:

http://www.tutorialspoint.com/cprogramming/c_pointer_to_an_array.htm

I understand that pointers use dynamic memory allocation so they are much more flexible then a built in array, but if you already have an existing array, don't you already have static memory allocation for that array? Why bother assigning a pointer? Regardless of the pointer, doesn't the program still allocate static memory to the array anyway?

[Duthomhas]

No matter how you get the memory, it has to be an allocated array in memory (meaning a block of memory your program is allowed to access).

Pointers are simply much more flexible than arrays.
Further, arrays are not first class objects. (You can't pass an array to a function, for example. You pass a pointer to the first element in the array.)

Hope this helps.

[MiiNiPaa]

Also pointers are often used as iterators to the array elements:

constexpr std::size_t n = 100;
int foo[n];
//fill array
int partial_sum = 0;
int* const iend = foo + n;
for(int* icur = foo; ; icur != iend; ++icur) {
    partial_sum += *icur;
    *icur = partial_sum;
}

[Duthomhas]

Actually, iterators are modeled after pointers.
That's why they look so similar in use.