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Revision: 19816
at October 31, 2009 19:18 by jmiller
Initial Code 
function encode($val, $base=62, $chars='0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ') {
    // can't handle numbers larger than 2^31-1 = 2147483647
    $str = '';
    do {
        $i = $val % $base;
        $str = $chars[$i] . $str;
        $val = ($val - $i) / $base;
    } while($val > 0);
    return $str;
}

function decode($str, $base=62, $chars='0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ') {
    $len = strlen($str);
    $val = 0;
    $arr = array_flip(str_split($chars));
    for($i = 0; $i < $len; ++$i) {
        $val += $arr[$str[$i]] * pow($base, $len-$i-1);
    }
    return $val;
}

echo encode(2147483647); // outputs 2lkCB1
Initial URL 
http://programanddesign.com/php/base62-encode/
Initial Description 
If you have large integers and you want to shrink them down in size for whatever reason, you can use this code. Should be easy enough to extend if you want even higher bases (just add a few more chars and increase the base).
Initial Title 
Base62 Encode / Decode
Initial Tags 

                                

                                                            

                                    

                                        

                                        Initial Language
                                        

                                    

                                    
PHP