How do I access a specific array element if I have a pointer to a struct which has a pointer to and a array of structs?

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How do I access a specific array element if I have a pointer to a struct which has a pointer to an array of structs?

struct node {
int number;
};

struct queue {
struct node *array;
};

int main() {
struct queue *queues;
struct node *t;
queues = (struct red*)malloc(sizeof(struct queue));
queues->array = (struct node*)malloc(10 * sizeof(struct node));
queues->array->number = 5;
queues->(array + 1)->number = 6
}

What I have tried:

queues->array->number can access the first element,but how do i access other elements?

queues->(array + i)->number doesnt work and
queues->array[i]->number doesnt work

Posted 14-Apr-19 3:15am

ognjenjebot

Updated 14-Apr-19 3:40am

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Richard MacCutchan · Accepted Answer · 2019-04-14T03:25:00

Solution 1

You need to use the dot referencer since array[i] is a proper reference, rather than a pointer (I know it's confusing but that is the rule in C). So you should code it as follows:

C++

int i = 3; // or any other offset
queues->array[i].number = 6;

Posted 14-Apr-19 3:25am

Richard MacCutchan

OriginalGriff · Accepted Answer · 2019-04-14T03:26:00

First off, get it to compile! "red" is not declared:

queues = (struct red*)malloc(sizeof(struct queue));

I assume you meant:

queues = (struct queue*)malloc(sizeof(struct queue));

Then just use it as an array:

queues->array[1].number = 6;
struct node *n = queues->array;
for (int i = 0; i < 10; i++)
    {
    printf("%u\n", n[i]);
    }

Will give you:

(Though the zeros may be replaced with random data, depending on your compiler)