C dynamic memory allocation

statically, automatically dynamically

Static-duration variables are allocated in main memory, usually along with the executable code of the program, and persist for the lifetime of the program; automatic-duration variables are allocated on the stack and come and go as functions are called and return.

These limitations are avoided by using  dynamic memory allocation in which memory is more explicitly (but more flexibly) managed. Typically, by allocating it from heap

Type safety:

int *ptr;
ptr = malloc(10 * sizeof (*ptr));               /* without a cast */
ptr = (int *)malloc(10 * sizeof (*ptr));        /* with a cast */
ptr = reinterpret_cast<int *>(malloc(10 * sizeof (*ptr))); /* with a cast, for C++ */