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Student Name: __________________
Class and Section __________________
Total Points (20 pts) __________________
Due: Nov 6, 2017 before the class
Project: Validating Credit Cards
CSCI 1301 Introduction to Programming Principles
Armstrong Atlantic State University
Problem Description:
Credit card numbers follow certain patterns. A credit card number must have between 13
and 16 digits. It must start with:
4 for Visa cards
5 for Master cards
37 for American Express cards
6 for Discover cards
In 1954, Hans Luhn of IBM proposed an algorithm for validating credit card numbers.
The algorithm is useful to determine if a card number is entered correctly or if a credit
card is scanned correctly by a scanner. Almost all credit card numbers are generated
following this validity check, commonly known as the Luhn check or the Mod 10 check,
which can be described as follows (for illustration, consider the card number
4388576018402626):
1. Double every second digit from right to left. If doubling of a digit results in a two-digit
number, add up the two digits to get a single-digit number.
2. Now add all single-digit numbers from Step 1.
4 + 4 + 8 + 2 + 3 + 1 + 7 + 8 = 37
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5. If the result from Step 4 is divisible by 10, the card number is valid; otherwise, it is
invalid. For example, the number 4388576018402626 is invalid, but the number
4388576018410707 is valid.
Write a program that prompts the user to enter a credit card number as a long integer.
Display whether the number is valid or invalid.
Here are sample runs of the program:
Sample 1:
Sample 2:
Enter a credit card number as a long integer: 4388576018410707
4388576018410707 is valid
Analysis:
(Describe the problem including input and output in your own words.)
Design:
(Describe the major steps for solving the problem using the diagram like the one in the
book Figure 6.11)
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Coding: (Copy and Paste Source Code here. Format your code using Courier 10pts)
Name your class Exercise06_31
Testing: (Describe how you test this program)
Submit the following items:
1. Print this Word file and Submit to me before the class on the due day
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Code Solution:
import java.util.Scanner;
public class Test {
/** Get the result from Step 2 */
public static int sumOfDoubleEvenPlace(long number) {
int result = 0;
number = number / 10; // Starting from the second digit from left
while (number != 0) {
result += getDigit((int)((number % 10) * 2));
number = number / 100; // Move to the next even place
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public static boolean prefixMatched(long number, int d) {
return getPrefix(number, getSize(d)) == d;
}