I'm working on a url shortener. I based mine on this one https://github.com/phpmasterdotcom/BuildingYourOwnURLShortener and more or less took the function to create the short codes, because i couldn't come up with an algorithm myself:
<?php
convertIntToShortCode($_GET["id"]); // Test codes
function convertIntToShortCode($id) {
$chars = "123456789bcdfghjkmnpqrstvwxyzBCDFGHJKLMNPQRSTVWXYZ";
$id = intval($id);
if ($id < 1) {
echo "ERROR1";
}
$length = strlen($chars);
// make sure length of available characters is at
// least a reasonable minimum - there should be at
// least 10 characters
if ($length < 10) {
echo "ERROR2";
}
$code = "";
while ($id > $length - 1) {
// determine the value of the next higher character
// in the short code should be and prepend
$code = $chars[fmod($id, $length)] . $code;
// reset $id to remaining value to be converted
$id = floor($id / $length);
}
// remaining value of $id is less than the length of
// self::$chars
$code = $chars[$id] . $code;
echo $code;
}
?>
Although it works, some of my numbers (database id) output strange shortcodes:
1 -> 2 2 -> 3 ... 10 -> c 11 -> d 12 -> e ...
Is there any easy way i can modify this code, so that my generated short codes are longer than just one character (at least two or three characters for every shortcode), even for integers like 1, 2, 3 etc.?
Also is there anybody who can tell me, how this algorithm above works to output short codes for integers?
Thanks in advance