README.md

📦 This package is a sub-repo split of a PHP Validator which is currently under development.

✨ This can also be installed as a dependency for Payment Card library to validate Debit/Credit Cards.

Introduction

Luhn Algorithm to validate Payment Cards, IMEI numbers and other digits that needs Luhn validation.

Usage

Install

composer require thewebsolver/luhn-algorithm

Validate

Validation can be performed using any of the three OPTIONS presented below:

use TheWebSolver\Codegarage\LuhnAlgorithm;

// OPTION 1: Value passing via constructor.
$luhn     = new LuhnAlgorithm(79927398713);
$isValid  = $luhn->isValid();  // true
$checksum = $luhn->checksum(); // 70

// OPTION 2: Value passing via invocable class.
$luhn     = new LuhnAlgorithm();
$isValid  = $luhn(79927398713); // true
$checksum = $luhn->checksum();  // 70

// OPTION 3: Value passing via static method. In this case, There is no
// instance stored in memory & can only be used for one-off validation.
$isValid = LuhnAlgorithm::validate(79927398713); // true

Debug

From above Validation example, we can debug more details about the validation status and various state of each number when checkum was calculated.

var_dump( $luhn ); // Input value was: 79927398713

// The debug output.
array(4) {
  'isValid' =>
  bool(true)
  'digits' =>
  int(79947697723)
  'checksum' =>
  int(70)
  'state' =>
  array(11) {
    [0] =>
    array(2) {
      'doubled' =>
      bool(false)
      'result' =>
      int(7)
    }
    [1] =>
    array(2) {
      'doubled' =>
      bool(true)
      'result' =>
      int(9)
    }
    [2] =>
    array(2) {
      'doubled' =>
      bool(false)
      'result' =>
      int(9)
    }
    [3] =>
    array(2) {
      'doubled' =>
      bool(true)
      'result' =>
      int(4)
    }
    [4] =>
    array(2) {
      'doubled' =>
      bool(false)
      'result' =>
      int(7)
    }
    [5] =>
    array(2) {
      'doubled' =>
      bool(true)
      'result' =>
      int(6)
    }
    [6] =>
    array(2) {
      'doubled' =>
      bool(false)
      'result' =>
      int(9)
    }
    [7] =>
    array(2) {
      'doubled' =>
      bool(true)
      'result' =>
      int(7)
    }
    [8] =>
    array(2) {
      'doubled' =>
      bool(false)
      'result' =>
      int(7)
    }
    [9] =>
    array(2) {
      'doubled' =>
      bool(true)
      'result' =>
      int(2)
    }
    [10] =>
    array(2) {
      'doubled' =>
      bool(false)
      'result' =>
      int(3)
    }
  }
}

Composition

The Luhn Algorithm class is actually composed by using Luhn trait. This trait can be used elsewhere in separate class defined in your project or modify validation methods as per the project's requirement (latter of which seem unnecessary though).