C dynamic memory allocation and sizeof()

Question

I\'m having some trouble understanding the difference between these two code segments: I allocate space for an array of integers dynamically within my code with the followin

Answer 1

*arr is not the same as arr[8] since it's size is not known in compile time, and sizeof is a function of the compiler. So when your arr is *arr sizeof will return the size of the pointer (sizeof(int *))in bytes, while when your arr is arr[8], the sizeof will return the size of array of 8 integers in bytes (which is sizeof(int) * 8).

When you pass a pointer to array to a function, you must specify its size, because the compiler can't do it for you. Another way is to end the array with null element, and perform a while loop.