Question

I need generate codes from this letters

$a = array(
    'B','C','D','F','G','H','J','K','L','M','N','O',
    'P','Q','R','S','T','V','W','X','Y','Z','1','2',
    '3','4','5','6','7','8','9','0'
);

But there are 2 conditions: every code must be unique and contains 10 letters. I don’t want to get random because is unefficient. Instead, I want go for every letter e.g.:

1. BBBBBBBBBB
2. BBBBBBBBBC
3. BBBBBBBBBD

and so on.. Any ideas?

Answer 1

<?php

$a = array(
    'B','C','D','F','G','H','J','K','L','M','N','O',
    'P','Q','R','S','T','V','W','X','Y','Z','1','2',
    '3','4','5','6','7','8','9','0'
);

function key_increment (&$symbols, $position = null) 
{
    global $a;
    if ($position === null) $position = count($symbols) - 1;
    if ($position == -1) return;

    $index = $symbols[$position];
    $index ++;
    if (!isset($a[$index])) {
        $v = 0;
        key_increment ($symbols, $position-1);
    }
    $symbols[$position] = $value;
}

function generate($length, $total) 
{
    global $a;

    $symbols = array_fill(0, $length, 0);


        for ($i = 0; $i < $total; $i ++) {
            $code = '';
        foreach ($symbols as $index) {
            $code .= $a[$index];
        }
        echo $code;
        echo '<br />';

        key_increment($symbols);
    }
}

generate(3, 100);