Question

I have this function:

int firstHeapArray (IntHeapArray h) {
    if(!emptyHeapArray(h))
        return h.array[0];
}

It’s declared as int, and this is the IntHeapArray struct:

typedef struct intHeapArray {
    int *array;
    int size;
} IntHeapArray;

Can you say why I get this warning while compiling?

heap-test.c: In function ‘firstHeapArray’:
heap.h:31:1: warning: control reaches end of non-void function

Thank you very much.

Answer 1

The error message is stating that you have a method that is not a void return, but you’re reaching the end without returning a value. You need to return a valid int value.

The problem is here:

int firstHeapArray (IntHeapArray h) {
    if(!emptyHeapArray(h))
        return h.array[0];

    // If emptyHeapArray(h) is true, you reach here...

   // You need to return SOMETHING here to remove the warning
   return 0;
}