Arrays vs Pointers

Arrays and pointer have a lot in common. They are basically one with the other in C. But there are differences.

An ==array== is a contiguous chunk of values stored in memory. While a ==pointer== is a address to a specific place in memory.

So, the saying of not being able to get the size of a array in C is not totally wrong. But in the example here you can actually get the array size:

int arr[3];
printf("%lu", sizeof(arr)); // prints 12, meaning 12 bytes

So, you still can’t get the array size from pointers, because they can point to anything; random addresses, array elements, NULL, single integers, etc.

But when you pass an array into a function, you are automatically passing the pointer to the first element of the array. So, a lot of times, arrays will decay into pointers.

#cs