Is this approach using a dynamic array structure in C OK?

Question

I am just a beginner in C looking for a dynamic array structure and came across this youtube tutorial.

The Code uses pointers to create a dynamic array without using heap memory allocation like malloc(). I just wonder, if this approach is Ok or it will likely become a bug, because memory can be overwritten?

The Code:

#include "stdio.h"

typedef struct S_RacingCar {

    char name[8];
    int speed;

} RacingCar;

const int MaxCars = 4;

void PrintList() {
    printf("List Print...\n");
}

int AddCar(RacingCar *car) {
    printf("Enter Name And Speed: ");
    char input[16];
    fgets( input, 15, stdin);
    int ok = 0;

    int res = sscanf(input, "%s %d", car->name, &car->speed);

    if(res == 2) {
        ok = 1;
        printf("Added:%s Speed:%d\n\n",car->name,car->speed);
    } else {
        printf("Sorry, error parsing input\n\n");
    }
    return ok;
}

int main() {    

    RacingCar allCars[MaxCars];
    int numCars = 0;

    char command[16];
    char input[16];

    while( fgets( input, 15, stdin) ) {

        sscanf(input,"%s",command); 

        if ( strncmp(command, "quit", 4) == 0) {
            printf("\n\nBreaking...\n");
            break;      
        } else if ( strncmp(command, "print", 5) == 0) {
            PrintList();
        } else if ( strncmp(command, "add", 3) == 0) {
            if(numCars < MaxCars) {
                numCars += AddCar( &allCars[numCars] );
            } else {
                printf("Sorry List Is Full!!\n\n");
            }
        }
    }


    return 0;

}

Answer 1

There is no dynamic array in your code

RacingCar allCars[MaxCars];

Here, the max size of array is already defined as MaxCars. The thing that might seem to confuse you is that from main the reference to the array is sent to other functions where the value is being added into the array. To create a dynamic array in C, you use malloc, calloc or realloc .