Can you explain the purpose of array+5 in this program?

Question

I understand how most of it works, except for the second line in the main function: int* end = array+5;. How does that line work?

#inlcude <iostream>
int main()
{
    int array[] = {10, 20, 29, 200, 2};

    int* end = array+5;
    for(int* it = array; it != end; ++it)
    {
        std::cout << *it << std::endl;
    }
}

It is supposed to just print every element in the list.

Answer 1

it != end;

means that it reached the position [5], which is one after the last (4).

int* end = array + 5; 

simply creates a variable pointing to that [5] position.

It works, but a much more clean and safe version is:

for(int i = 0 ; i < 5 ; i++)
{
    std::cout << it[i] << std::endl;
}

Of course, you can replace the hardcoded 5 with sizeof(array)/sizeof(int), or, even better, use a std::array.

std::array arr<int,5> = {10, 20, 29, 200, 2};
for(int i = 0 ; i < arr.size() ; i++)
{
    std::cout << arr[i] << std::endl;
}

or

 std::array arr<int,5> = {10, 20, 29, 200, 2};
 for(auto& it : arr)
 {
    std::cout << it << std::endl;
 }

The latter forms are as fast as the plain raw array, but a lot safer.