error: expected identifier before ‘(’ token queue

Question

struct nodePatient {
    struct Patient * patient; 
    struct nodePatient * next;
};

struct linkedQueue {
    struct nodePatient * firstNode;
    struct nodePatient * lastNode;
    unsigned size;
    unsigned maxSize;
};


struct PriorityQueue {
    struct linkedQueue * queue;
    int size;
    unsigned minPriorityValue;
};



struct PriorityQueue * createPriorityQueue(unsigned minPriorityValue) {
    struct PriorityQueue * newPriorityQueue = (struct PriorityQueue*) malloc (sizeof (struct PriorityQueue));
    newPriorityQueue->queue = (struct linkedQueue*) calloc (minPriorityValue+1, sizeof (struct linkedQueue));
    int i;

    newPriorityQueue->minPriorityValue = minPriorityValue;
    for(i = 0; i < minPriorityValue; i++) {
        newPriorityQueue->(queue+i)->maxSize = UNLIMITED_SIZE;
        newPriorityQueue->(queue+i)->size = 0;
        newPriorityQueue->(queue+i)->firstNode = NULL;
        newPriorityQueue->(queue+i)->lastNode = NULL;
    } 
    return newPriorityQueue;    
}

This is a part of my code and when i'm trying to compile i'm getting the fallowing errors:

What is it wrong in it?

Welcome to Stack Overflow! [Please see this discussion on why not to cast the return value of `malloc()` and family in `C`.](http://stackoverflow.com/q/605845/2173917). — Sourav Ghosh, Apr 26 '16 at 14:30
Just saying, `newPriorityQueue->(queue+i)->maxSize` is a pretty weird way to write a meaningful and understandable code. — Sourav Ghosh, Apr 26 '16 at 14:32
You could do `(newPriorityQueue->queue+i)->maxSize = ...`. Not pretty, but should work. The traditional way would be `newPriorityQueue->queue[i].maxSize = ...`. — EOF, Apr 26 '16 at 14:39
You are expoected to post text as text, not links or images. — too honest for this site, Apr 26 '16 at 14:58
"*i'm getting the fallowing errors: enter image description here*" so what keeps you from entering an image description though? — alk, Apr 26 '16 at 16:12

score 1 · Answer 1 · answered Apr 26 '16 at 14:57

The expression

newPriorityQueue->(queue+i)

is wrong given your object types. Due to operator precedence (queue+i) is evaluated first. However, queue is not an independent variable. It is a member of the struct.

Hence, you need to use:

(newPriorityQueue->queue+i)

A syntactically correct line would be:

(newPriorityQueue->queue+i)->maxSize = UNLIMITED_SIZE;

You could make it more readable by using:

newPriorityQueue->queue[i].maxSize = UNLIMITED_SIZE;

error: expected identifier before ‘(’ token queue

1 Answers1