CODEWITHSUNDEEP
php
JJJollyjim
JJJollyjim

Reputation: 6247

Creating a sequence from 1-ZZZZZZZZ in PHP

I am working on something where I need to generate the sequence 1,2,3...a,b,c,d...z,11,12,13...aa,ab,ac...zzzzzzzz, using php. This will only ever have to happen once, so it dosen't need to be very fast.

Thanks!

Upvotes: 1

Views: 546

Answers (2)

niggles
niggles

Reputation: 1034

I recently had to do this with a non-standard set of character (they left out certain characters).

I put together a few functions I found on the net and got:

// this array misses a few letters due to the special naming convention
private $alphabet = array('0', '1','2','3','4','5','6','7','8','9','A','B','C','D','E','F','G','H','J','K','L','M','N','P','Q','R','S','T','U','V','W','X','Y','Z');

private function createDecimalFromCode($string){

        $decimal = 0;
        $base = count($this->alphabet);
        $charset = implode($this->alphabet, '');
        $charset = substr($charset, 0, $base);

        do {

            $char   = substr($string, 0, 1);
            $string = substr($string, 1);

         $pos = strpos($charset, $char);
         if ($pos === false) {
            $error[] = "Illegal character ($char) in INPUT string";
            return false;
         } // if
         $decimal = ($decimal * $base) + $pos;
        } while($string <> null);

        return $decimal;


    }

    private function  createCodeFromDecimal($decimal){

        $s = '';
        while($decimal > 0) {

            $s = $this->alphabet[$decimal%sizeof($this->alphabet)] . $s;
            $decimal = floor($decimal/sizeof($this->alphabet));
        }



return $s == '' ? '0' : $s;
}

Essentially I take my last created code, convert it to a decimal, add 1 and then convert that back to the next alphanumeric code.

Upvotes: 0

Jonah
Jonah

Reputation: 10091

function incrementAlphanumeric($number) {
    return base_convert(base_convert($number, 36, 10) + 1, 10, 36);
}

echo incrementAlphanumeric(9); // outputs "a"

To populate an array:

$number = 1;
$numbers = array();
while ($number != 'zzzzzzzz') {
    $numbers[] = $number;
    $number = incrementAlphanumeric($number);
}

http://php.net/base-convert

Upvotes: 2

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