objective c - Convert decimal to binary and return array

Question

probably there is a smart way to do that , but anyway i get error on this :

-(int*)decimalBinary:(int)decimal
{
    int i=0;
    int *bin;
    while (decimal!=0)
    {
        bin[i]=decimal%2;
        decimal=decimal/2;
        i++;
    }

    return bin;

}

on the modulo line . why ? And whats the better way to get it to array ?

Answer 1

Declaring

int *bin;

sets aside space for a pointer but doesn't make it point to an object. It is crucial to initialize bin before using it.
To solve your problem you can declare an array bin[4] in caller function (int main) and then pass *bin to your calling function.