支票数字大写转换器

In the last post, we saw that Credit Card numbers are not random and it can be validated using Luhn Algorithm and I wrote a java program for credit card number validation.

在上一篇文章中，我们看到信用卡号不是随机的，可以使用Luhn算法进行验证，并且我编写了一个Java程序来进行信用卡号验证 。

A credit card number last digit is called Check Digit and its appended to a partial credit card number to generate the complete valid credit card number. For example, if we have a partial card number of 15 digits as 123456789012345 then using Luhn algorithm, we find that check digit should be 2, so the valid credit card number will be 1234567890123452.

信用卡号的最后一位数字称为校验位，并将其附加到部分信用卡号后以生成完整的有效信用卡号。 例如，如果我们有一个15位数字的部分卡号，例如123456789012345，则使用Luhn算法，我们发现校验位应为2，因此有效的信用卡号将为1234567890123452。

Here I am providing a method in java to generate the check digit for a partial credit card number.

在这里，我提供了Java中的一种方法来生成部分信用卡号的校验位。

GenerateCheckDigit.java

GenerateCheckDigit.java

package com.journaldev.design.test;public class GenerateCheckDigit {public static void main(String[] args) {long l = 123456789012345L;int cd = generateCheckDigit(l);System.out.println("Valid card number="+l+cd);}private static int generateCheckDigit(long l) {String str = Long.toString(l);int[] ints = new int[str.length()];for(int i = 0;i< str.length(); i++){ints[i] = Integer.parseInt(str.substring(i, i+1));}for(int i = ints.length-2; i>=0; i=i-2){int j = ints[i];j = j*2;if(j>9){j = j%10 + 1;}ints[i]=j;}int sum=0;for(int i = 0;i< ints.length; i++){sum+=ints[i];}if(sum%10==0){return 0;}else return 10-(sum%10);}}

Once the valid account number is generated by adding check digit to the partial credit card number, you can validate it using my last program to validate credit card number.

通过在部分信用卡号上添加校验位来生成有效帐号后，您就可以使用我的上一个程序来验证信用卡号了 。

翻译自: https://www.journaldev.com/1449/credit-card-check-digit-generator-java-program

支票数字大写转换器