Allo.
I am finishing up my coding project and I am going nuts trying to figure out what I'm doing wrong. I thought I finished my ISBN checker code properly, but when I finish imputing the ISBN number that is valid, I get "The ISBN number is valid", but I also get "Your ISBN number is not valid. The check number value should be 7". I am getting both responses. I get this each and every time I enter the info. What's going on here. I'm going crazy. haha.
public static void main(String[] args)
{
//prepare keyboard reader
Scanner kbReader = new Scanner(System.in);
int checkDigitSum = 0;
//starts loop to read all 9 digits
for(int i=1; i<=9 ;i++)
{
//prompt for input of digit i
System.out.print("Enter digit" + i + " of ISBN:");
//reads next digit
int digit = kbReader.nextInt();
//this line adds this digit times its order to the cumulative
checkDigitSum = checkDigitSum + (i * digit);
}
//prompts for the check value
System.out.print("Enter the check value:");
//read Check Value and convert to lowercase value
String checkValue = kbReader.next().trim().toLowerCase();
//compute the calculated check value as remainder of division to 11
int remainder = checkDigitSum % 11;
//Convert to string
String calculatedCheckSumValue = Integer.toString(remainder);
//if the remainder is greater than 10 the check value is X
if(remainder>=10)
calculatedCheckSumValue = "x";
//if the value matches it is valid
if( checkValue.equals( calculatedCheckSumValue)){
System.out.println("Your ISBN is valid.");
}
else{
}
//if it dosen't match
System.out.println("Your ISBN is not valid.The check value should be " + calculatedCheckSumValue);
}}