cs50 pset1 credit expected expression error

Question

So, I have gotten rid of all the errors and got the code to the point to prompt the user for the credit card number and output an answer the only problem is the program falls thru to invalid every time and never prints a credit card brand. The updated code is posted below any help is appreciated.

Thank you,

#include <stdio.h>
#include <cs50.h>
#include <math.h>
#include <string.h>

long checklength();
long checksum();
long cardBrand(long askPositiveLong, long checklength, long checksum);


int main()
{
    long positiveLong = 0;
    int ccn = 0;
    long askPositiveLong;
    do
    {
        askPositiveLong = get_long("Enter valid credit card # ");
    }while(askPositiveLong < 0);
    printf("%li\n", cardBrand(ccn, positiveLong, askPositiveLong));
}

long checklength(ccn)
{
    if(ccn == 13 || ccn == 15 || ccn == 16)
    {

        return true;
        return false;
    }
    return ccn;   
}  


long checksum(positiveLong)
{
    int sum = 0;
    for(int i = 0; i > positiveLong; i++)
    {
        if (i % 10 == 0)
        {
            int digit = (2*(positiveLong%10));
            sum += (digit/10 + digit%10);

        }
        else
        {
        sum += (18/10 == 1) + (18%10 == 8);
        }
    }
    if(sum % 10 == 0)
    {
    return true;
    return false;
    }
    return positiveLong;
}
long cardBrand (long askPositiveLong, long checklength, long checksum)
{
    if (askPositiveLong >= 340000000000000 && askPositiveLong < 350000000000000)
    {
        printf("AMEX\n");
    }
    else if (askPositiveLong >= 370000000000000 && askPositiveLong < 380000000000000)
    {
        printf("AMEX\n");
    }
    else if (askPositiveLong >= 5100000000000000 && askPositiveLong < 5600000000000000)
    {
        printf("MASTERCARD\n");
    }
    else if (askPositiveLong >= 4000000000000 && askPositiveLong < 4100000000000)
    {
        printf("VISA\n");
    }
    else if (askPositiveLong >= 4000000000000000 && askPositiveLong < 4100000000000000)
    {
        printf("VISA\n");
    }
    else
    {
    printf("INVALID");
    }
    return askPositiveLong;
}

Answer 1

Look at the line in question:

if(askPositiveLong >= 340000000000000 && askPositiveLong < 350000000000000)
   || (askPositiveLong >= 370000000000000 && askPositiveLong < 380000000000000)

How are the parentheses???? Anything missing?

I wonder if this problem exists anywhere else??? ;-)

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