CODEWITHSUNDEEP
phprandomlong-integeruniqueidentifier
creator
creator

Reputation: 681

How to get Long 19 digits random numbers at PHP?

So I need to make unique purchase number of mobile game. Each user's buying of in-app-purchase item record should be attached by unique long type 19 digits numbers from php code and stored to mysql DB.

But how can I actually make random 19 digits numbers?

I tried like this but errors.

$num_str = sprintf("%19d", mt_rand(1, 9999999999999999999));

Upvotes: 3

Views: 5024

Answers (3)

Vishal Rambhiya
Vishal Rambhiya

Reputation: 749

$randNumber = date("YmdHis").rand(11111,99999);

Upvotes: -2

Sougata Bose
Sougata Bose

Reputation: 31749

You have to do something like - 

$num_str = sprintf("%10d", mt_rand(1, mt_getrandmax())).sprintf("%9d", mt_rand(1, mt_getrandmax()));
if (strlen($num_str) < 19)
    $num_str = str_pad($num_str, 19, rand(0, 9), STR_PAD_RIGHT);
else if(strlen($num_str) > 19)
    $num_str = substr($num_str, 0, 19);
echo $num_str;

The distribution of mt_rand() return values is biased towards even numbers on 64-bit builds of PHP when max is beyond 2^32. This is because if max is greater than the value returned by mt_getrandmax(), the output of the random number generator must be scaled up.

Upvotes: 0

catzilla
catzilla

Reputation: 1981

you can also try this:

function random19() {
  $number = "";
  for($i=0; $i<19; $i++) {
    $min = ($i == 0) ? 1:0;
    $number .= mt_rand($min,9);
  }
  return $number;
}

echo random19();

which would output some random 19 numbers: 6416113158912395605

Upvotes: 4

Related Questions