Thread: ASSIGNMENT HELP

i tried at least 50 times for this code to work and i just can't get it to work. can someone tell me how to do it?


Assignment - Repetition

In the nine-digit Social Insurance Number given to each person having a job or filing an income tax return in Canada, the ninth digit is a check digit that is used to test the validity of the other digits in the SIN. The ninth digit is determined by the following procedure.

a) Double the 2nd, 4th, 6th, and 8th digits.
• If the result is two digits long, add the digits together
b) Add the digits of the numbers found in step (a).
c) Add the 1st, 3rd, 5th, and 7th digits
d) Add the numbers found in steps (b) and (c).
e) Subtract the unit (ones digit) digit of the result of step (d) from 10 and note the units digit of the result. For the SIN to be valid, its ninth digit must have this value.

Write a program that repeatedly reads nine-digit numbers and determines whether or not each number is a valid SIN, The program should stop when it reads the value 999999999.

Originally Posted by Norm

Take them one at a time. What problem do you have doing the first step?

i don't know how to get each digit on it's own... i tried %10 to get the last digit but i don't understand how i would throw this all into a for loop!

Originally Posted by Norm

Are you allowed to convert the number to a String? That would make getting the digits by their position easier.

yeah you can do that! my teacher said you're allowed to do anything as long as it's in a loop but i dont know how to do it.. like i know the syntax but don't know how to apply it here.

i don't know how to convert it to from a int to a string then back ...

what do you suggest would be the best way to do it

Originally Posted by Norm

Read it as a String.

i'm a java noob... could you get my program started? like just until the loop cause i tried to put it as a string but i don't know how i would get the 2nd, 4th, 6th, 8th digits out of it! im STRUGGLING! thanks!

char c1 = SIN.charAt(1);
char c2 = SIN.charAt(3);
char c3 = SIN.charAt(5);
char c4 = SIN.charAt(7);
int num1 = c1*2;
if (num1>9){
Integer.toString(num1);
char num1_1 = ((num1.charAt(1))) +(num1.charAt(2));

Exception in thread "main" java.lang.Error: Unresolved compilation problems:
Cannot invoke charAt(int) on the primitive type int
Cannot invoke charAt(int) on the primitive type int

i don't know what i did wrong, any suggestions? maybe where i should move the conversion statement

	// Prompt for SIN Card number as string, convert to integer to get check digit, output the check digit, convert back to string for proccess
 
		System.out.println("Please enter your SIN card number: ");
		String SIN = in.nextLine();
		int SIN1 = Integer.parseInt(SIN);
		int checkdigit = SIN1%10;
		System.out.println("The checkdigit is: " + checkdigit);
		Integer.toString(SIN1);
 
		//Start the process
 
		char c1 = SIN.charAt(1);
		char c2 = SIN.charAt(3);
		char c3 = SIN.charAt(5);
		char c4 = SIN.charAt(7);
		int num1 = c1*2;
		if (num1>9){
			Integer.toString(num1);
			char num1_1 = ((num1.charAt(1))) +(num1.charAt(2));
 
		}

i'm completely lost... this is my first assignment using java, i have experience with python but this is on another level! help please! what should i do !!

working on your program here. Taking some time but I am developing a solution for it.

okay thanks so much! but why is it that when i put down 888888888 as the SIN number, and do this

                char c1 = SIN.charAt(1);
		char c2 = SIN.charAt(3);
		char c3 = SIN.charAt(5);
		char c4 = SIN.charAt(7);
		int num1 = c1*2;
 
		if (num1>9){
		int num1_1 = (num1%10) + (num1/10);
		System.out.println(num1%10);
		System.out.println(num1/10);
		System.out.println(num1_1);
		}

i get the results:
2
11
13

when i should be getting:
1
6
7

NOTE: i just put the system.out statements to see what each answer was, for the final code i would not display this.

Originally Posted by Norm

What was the value of num1? You should also print that also.

woah, i checked the value of num1 and i got 112!!
any thoughts on why?

and yeah, ill do that for sure next time!

Originally Posted by Norm

What was the value of num1? You should print that also.

The value of the char '8' is not the int 8? Copy and execute this:

 System.out.println("'8'="+ (int)'8');  // '8'=56

i copy and pasted it into the compiler and got '8' =56
so i would have to subtract '8' by 0 to get 8?

1. Take the user input as string

2. Select the digit at each place and save it into an array on integers. It can be done by
int numbers = new int[9];
for(int i = 0; i < 9; i++)
{
char a = stringAt(i);
numbers[i] = parse the char to integer.
}

3. int total = 0;
for loop(int i = 2; i < 9; i = i +2)
{ int temp = 0;
temp = numbers[i] * 2;
if(temp > 9)
total += temp/10;
total += temp%10;
else
total += temp;
}

4. for loop(int i = 1; i < 9; i = i+2)
{total += numbers[i];}

5. int test = total%10 - total/10;

6. if(test == numbers[8])
SSN is correct.
else
SSN is wrong

Hope this helps

Try my solution from scratch. I have tried it with code. It won't take long. I can't pose code here because of the regulations.