How do I determine the size of my array in C?

Question

How do I determine the size of my array in C? That is, the number of elements the array can hold?

Answer 1

Hi,

It is actually very easy. You just need to get the size in bytes of the entire array and divide that number by the size in bytes of one of the array's element. For instance:

int a[10];

size_t num_elements = sizeof(a) / sizeof(a[0]);

Explanation: (assuming int size is 4 bytes)

sizeof(a) = size_of_1_element * number_of_elements = 4 bytes * 10 bytes = 40 bytes.

sizeof(a[0]) = 4 bytes.

Then, num_elements = 40 bytes / 4 bytes = 10 bytes.