How to create and use a dynamic array?

Question

C++ / C#

How to create and use a dynamic array in C?
It’s just that I don’t know in advance how many values ​​will be in it, is it for this that dynamic ones are used?

Answer 1

Let N be the number of elements in the array:

#include "stdlib.h"

...

int * arr = (int*)malloc(sizeof(int) * N);
...
for(int i = 0; i < N; ++i)
   printf("%d ", arr[i]);
printf("\n");
free(arr);

Here, for brevity, checking for memory allocation errors is omitted /