Base62

<?php

/**

 * Base62 将整型转为62进制数字（有大数问题）

 * @author Sundj

 * @since 2014.04.07

 */

class Base62 {

const BASE = 62;
static $baseChars = ‘0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ‘;
public function encode($number) {

        $output = ‘‘;
do {

            $reminder = $number % Base62::BASE;

            $output = Base62::$baseChars[$reminder] . $output;

            $number = ($number - $reminder) / Base62::BASE;

        } while($number > 0);
return $output;

    }
public function decode($input) {

        $length = strlen($input);
$number = 0;

        $baseChars = array_flip(str_split(Base62::$baseChars));

        for($i = 0; $i < $length; ++$i) {

            $number += $baseChars[$input[$i]] * pow(Base62::BASE, $length - $i - 1);

        }

        return number_format($number, 0, ‘‘, ‘‘);

    }

}

Base62