Contents

<?php

function isValid($candidate)
{
    $sanitizedCandidate = str_replace(" ", "", $candidate) ;

    if (strlen($sanitizedCandidate) <= 1 || !ctype_digit($sanitizedCandidate)) {
        return false ;
    }

    $reversseCandidate = strrev($sanitizedCandidate) ;
    $sum = 0 ;

    for ($i = 1; $i < strlen($reversseCandidate); $i+=2) {
        $digit = 2 * intval($reversseCandidate{$i}) ;

        if ($digit > 9) {
            $digit -= 9 ;
        }

        $sum += $digit ;
        $sum += intval($reversseCandidate{$i-1}) ;
    }

    return $sum % 10 == 0 ;
}

Version data entries

275 entries across 275 versions & 1 rubygems

Version	Path
trackler-2.2.1.98	tracks/php/exercises/luhn/example.php
trackler-2.2.1.97	tracks/php/exercises/luhn/example.php
trackler-2.2.1.96	tracks/php/exercises/luhn/example.php
trackler-2.2.1.95	tracks/php/exercises/luhn/example.php
trackler-2.2.1.94	tracks/php/exercises/luhn/example.php
trackler-2.2.1.93	tracks/php/exercises/luhn/example.php
trackler-2.2.1.92	tracks/php/exercises/luhn/example.php
trackler-2.2.1.91	tracks/php/exercises/luhn/example.php
trackler-2.2.1.90	tracks/php/exercises/luhn/example.php
trackler-2.2.1.89	tracks/php/exercises/luhn/example.php
trackler-2.2.1.88	tracks/php/exercises/luhn/example.php
trackler-2.2.1.87	tracks/php/exercises/luhn/example.php
trackler-2.2.1.86	tracks/php/exercises/luhn/example.php
trackler-2.2.1.85	tracks/php/exercises/luhn/example.php
trackler-2.2.1.84	tracks/php/exercises/luhn/example.php
trackler-2.2.1.83	tracks/php/exercises/luhn/example.php
trackler-2.2.1.82	tracks/php/exercises/luhn/example.php
trackler-2.2.1.81	tracks/php/exercises/luhn/example.php
trackler-2.2.1.80	tracks/php/exercises/luhn/example.php
trackler-2.2.1.79	tracks/php/exercises/luhn/example.php