check digit

基本解释

A binary check digit; for example , a parity bit.
一个二进位校验位元，例如奇偶位。
The card number, a thirteen- or sixteen-digit string with a check digit
信用卡号，13 或 16 位数字组成的字符串，包括一个校验位
I'm trying to make a program that check the ISBN number and sees if it has the correct check digit, if it doesn't have the check digit it will add one.
我试图制作一个程序，检查ISBN号码，看看它是否有正确的校验位，如果没有校验位，它将添加一个。

Glancing at the bottom, this is pretty arbitrary, but I chose to format my string as follows: % 1f so at the bottom here I'm printing out %.1f, which quick sanity check means print just one digit after the decimal place.
看下这个底部，这个是相当随意的，但我选择把我的字符串格式化成这样：,所以在这个底部我打印输出，提醒一下，这是一个只打印出,小数点后一位的方法。
哈佛公开课 - 计算机科学课程节选

The random 18-digit code plus two check digits will have a four-digit prefix added and it will have intelligence in it.
FORBES: America's Attempted Domination Of LEI Slams into FSB Wall
All that the user needs to do is swipe the card at the existing check-out machine and enter a four digit PIN.
FORBES: eBay Is Charged For $50 With PayPal's Discover Partnership
The lower that two digit number is - like say 05 - the sooner your check gets cut.
NPR: Retailers Hope to Get a Piece of Taxpayer Rebates

a digit derived from and appended to a string of data digits, used to detect corruption of the data string during transmission or transcription