E2140 expression must have integral or unscoped enum type

Question

int *fillArray(int* array,const int arraySize, const int min, const int max) 
{ 
    srand(time(0));
    for (size_t i = 0; i < arraySize; i++) 
    { 
        array[i] = rand % (max - min + 1) - min; 
    } 
}

You likely meant `rand()`, with a pair of parens. The compiler thinks you are trying to apply the remainder operator to a function pointer, which of course doesn't make sense. — Igor Tandetnik, Feb 16 '21 at 04:58
Unrelated, but see also [srand() — why call it only once?](https://stackoverflow.com/questions/7343833/srand-why-call-it-only-once). — dxiv, Feb 16 '21 at 05:08

score 1 · Answer 1 · answered Feb 16 '21 at 04:59

One error in your code is that rand is a function. To get a random number using that function you need to call it like so:

int random = rand();

But in here: array[i] = rand % (max - min + 1) - min; your calling the modulus operator on a function pointer. This is invalid. I guess what you were looking for is this:

array[i] = rand() % (max - min + 1) - min;

Another issue is that your not returning anything from the function. This will lead to undefined behavior. Make sure that your always return something (except for functions with a void return type).

int *fillArray(int* array,const int arraySize, const int min, const int max) 
{ 
    srand(time(0));
    for (size_t i = 0; i < arraySize; i++) 
    { 
        array[i] = rand() % (max - min + 1) - min; 
    } 

    return array;    // Return the modified array.
}

E2140 expression must have integral or unscoped enum type

1 Answers1