What is the Luhn Algorithm Test?
The Luhn Algorithm, also known as the mod 10 algorithm, is a simple checksum formula used to validate a variety of identification numbers, most notably credit card numbers.
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How to Use the Luhn Algorithm Test
1. Start by reversing the digits of the number. 2. Double every second digit. 3. If doubling of a digit results in a number greater than 9, subtract 9 from the product. 4. Add all the digits together. 5. If the total modulo 10 is equal to 0, then the number is valid.
luhn algorithm verification test
Example
Let's say we want to validate the number 4388576018402626. Reversing the digits gives 6264186805583843. Doubling every second digit and subtracting 9 if greater than 9 gives 6261818644843836. Adding all digits together yields 68, which is divisible by 10, making the number valid.
Why is the Luhn Algorithm Important?
The Luhn Algorithm helps prevent accidental errors and provides an extra layer of security for credit card transactions. It ensures that the number is correct and has not been manipulated in any way.