Question

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What are the barriers to understanding pointers and what can be done to overcome them?

i am really not familiar to c and pointers, I want to understand what is going on here :

typedef struct {
        int q[QUEUESIZE+1];
        int first;
        int last;
        int count;
} queue;
init_queue(queue *q)
{
        q->first = 0;
        q->last = QUEUESIZE-1;
        q->count = 0;
}

Is that correct to think that : q->first = 0 implies that if one assign to the ‘0’ address some value ‘val’, then *(q->first) will return ‘val’ ?

Answer 1

q->first is a short hand for (*q).first
The parenthesis are necessary because . would be evaluated before the dereference * and since q is a pointer well q.first == NOT A VALID THING

---

queue aQ;
init_queue(&aQ);

the function init_queue take a pointer to a queue not a pointer to an int.
The role of this function is to initialize all the field of the structure to be usable by other function at a latter time.