How to free a struct array in C

Question

I have a struct array like this

typedef struct {
    char *name[50];
    int score;
} score;

Memory is allocated to that array like this

score *scores = (score *) malloc(sizeof(score) * size);

I need to do an if-check and regarding to that check I am deallocating that memory space. So right now, I have 2 questions in my mind

1. Why can't I just free-up space like this ?

for (int i = 0; i < size; i++) {
        if (scores[i].score == scoreToBeDeleted) {
            free(scores[i].name);
            free(&(scores[i].score));
            free(&(scores[i]));
        }
    }

2. Should I shift the elements of the array as I remove records ?

Answer 1

You can't deallocate your struct variables because you haven't allocated them explicitly, you have allocated the array of struct scores.

/* Allocate scores */
scores *scores[size];
for (size_t i = 0; i < size; i++) {
    /* Allocate scores individually */
    scores[i] = (score *) malloc(sizeof score);
}

/* Deallocate scores */
for (int i = 0; i < size; i++) {
        if (scores[i]->score == scoreToBeDeleted) {
            free(scores[i];
        }
    }

This way you can achieve your desired behavior. Or you could use linked list of scores.