Why isn't the size of an array parameter the same as within main?

Question

Why isn\'t the size of an array sent as a parameter the same as within main?

#include 

void PrintSize(int p_someArray[10]);

int main () {
           


        

Answer 1

You can't pass arrays to functions.

If you really wanted to print the size, you could pass a pointer to an array, but it won't be generic at all as you need to define the array size for the function as well.

#include 

void PrintSize(int (*p_anArray)[10]);

int main(void) {
    int myArray[10];
    printf("%d\n", sizeof(myArray)); /* as expected 40 */
    PrintSize(&myArray);/* prints 40 */
}

void PrintSize(int (*p_anArray)[10]){
    printf("%d\n", (int) sizeof(*p_anArray));
}