Generate Random ID's

[Dysan]

Hi,

How do I randomly generate 6 character ID's, containing characters 1-9 and A-Z (Uppercase)?

[Derick88]

The characters won't be Uppercase, but it work fine..

function randomString($length)
{
    $string = md5(time());
    $highest_startpoint = 32-$length;
    $randomString = substr($string,rand(0,$highest_startpoint),$length);
    return $randomString;
}

$id = randomString(6);

[laserlight]

This is a near duplicate of the latter part of Auto Number (Increment by 10), but is ironically better placed since that thread had more than one question.

I am afraid that the requirements is a little different in that Dysan now wants the output to consist of [1-9A-Z], i.e., 35 possible characters. md5() alone will not cut it, though we could use it in conjunction with hexdec and base_convert(), methinks.

[roscor]

try this, i use something similar to generate random passwords which i then email to users.

function generate_id()
{
 $salt = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
  srand((double)microtime()*1000000);
 $id = "";
//generates random 6 character id 
  for($count = 0; $count < 6; $count++)
 {
    $num = rand() % 33;
    $tmp = substr($salt, $num, 1);
    $id = $id.$tmp;
  }
  return $id;
} 
$randid = generate_id(); 

[laserlight]

try this, i use something similar to generate random passwords which i then email to users.

If you want to generate it that way, then it should be:

function generate_id($length = 6)
{
    $range = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';
    $max = strlen($range) - 1;

// Generates random id of length $length.
$id = '';
for ($count = 0; $count < $length; $count++)
{
    $id .= $range[rand(0, $max)];
}
return $id;
}

[roscor]

Thanks laserlight, I have just noticed that using my previous code it produced a random id but did not include numbers, was that because of my code?

roscor

[laserlight]

I have just noticed that using my previous code it produced a random id but did not include numbers, was that because of my code?

For your example, it would not include the numbers 8, 9, and 0, but other than that if you did not get any numeric output, it was a matter of chance.