如何在php中编写带前缀的唯一优惠券代码

Question

I am trying to write prefixed unique coupon code for get the chance to be a intern at one company. It went well so far, my code is generating 250st, 10 length of codes every time I refresh the page. However, I am issuing a problem with prefixed part. Normally coupon code is looking like this, just one example "1SC476XY3B" but I want every code to start "AB" and then 8 length of code so total will be 10. Can you help me guys? All help will be appreciated, thanks.

<?php

function unique_coupon_codes($number_of_codes,$exclude_codes_array='',$code_length = 10)
{

$characters = "0123456789QWERTYUIOPASDFGHJKLZXCVBNM";

$unique_codes = array();
for($j = 1 ; $j <= $number_of_codes; $j++)
{
    $code = "";
    for ($i = 1; $i <= $code_length; $i++)
    {
        $code .= $characters[mt_rand(0, strlen($characters)-1)];
    }

    if(!in_array($code,$unique_codes))
    {
        if(is_array($exclude_codes_array))
        {
            if(!in_array($code,$exclude_codes_array))
            {
                $unique_codes[$j] = $code;
            }
            else
            {
                $j--;
            }
        }
        else
        {
            $unique_codes[$j] = $code;
        }
    }
    else
    {
        $j--;
    }
}
return $unique_codes;
}

echo '<h1>Unique Coupon Codes</h1>';
echo '<pre>';
print_r(unique_coupon_codes(250,'',10));
echo '</pre>';

Answer 1

It needs a minor change while initializing $code variable. Change $code = ""; to $code = "AB"; And call unique_coupon_codes function as

print_r(unique_coupon_codes(250, '', 8));

Here generate a unique code of 8 digits as you already have prefix AB of length 2 characters.