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-2.2.1.78	tracks/php/exercises/luhn/example.php
trackler-2.2.1.77	tracks/php/exercises/luhn/example.php
trackler-2.2.1.76	tracks/php/exercises/luhn/example.php
trackler-2.2.1.75	tracks/php/exercises/luhn/example.php
trackler-2.2.1.74	tracks/php/exercises/luhn/example.php
trackler-2.2.1.73	tracks/php/exercises/luhn/example.php
trackler-2.2.1.72	tracks/php/exercises/luhn/example.php
trackler-2.2.1.71	tracks/php/exercises/luhn/example.php
trackler-2.2.1.70	tracks/php/exercises/luhn/example.php
trackler-2.2.1.69	tracks/php/exercises/luhn/example.php
trackler-2.2.1.68	tracks/php/exercises/luhn/example.php
trackler-2.2.1.67	tracks/php/exercises/luhn/example.php
trackler-2.2.1.66	tracks/php/exercises/luhn/example.php
trackler-2.2.1.65	tracks/php/exercises/luhn/example.php
trackler-2.2.1.64	tracks/php/exercises/luhn/example.php
trackler-2.2.1.63	tracks/php/exercises/luhn/example.php
trackler-2.2.1.62	tracks/php/exercises/luhn/example.php
trackler-2.2.1.61	tracks/php/exercises/luhn/example.php
trackler-2.2.1.60	tracks/php/exercises/luhn/example.php
trackler-2.2.1.59	tracks/php/exercises/luhn/example.php