Why can't we declare an array dynamically?

Question

Can we do something like asking the user for the value of a variable, say "size" and then doing later in the code something like:

int array[size];

? If no, why?

Answer 1

Yes you can. Say you want an array of integers, you can do it like that:

printf("What is the length of the array?\n");
int n = GetInt();
int numbers[n];

for (int i = 0; i < n; i++)
{
    numbers[i] = GetInt();
}