Random Numbers

[Xurion]

Hi all,

I haven't played around with random numbers in PHP much before and I am trying to create a random number that has 12 digits (an order number for a client)

At the moment i have something like this:

[code]$mynum = ceil(rand(100000000000, 999999999999);[/code]

Thinking that this should generate a number from 100000000000 - 999999999999 it doesn't. It sometimes comes up with negative numbers like -5786142...?

Am I using this code in an incorrect way?

Thanks in advance.

[redarrow]

ceil is to round up numbers and floor is to round down numbers ok.

[code]
<?php
$rand=rand(7,2345566);
echo $rand;
?>
[/code]

[joshi_v]

Try this!


substr(md5(uniqid(rand(), true)), 0, 12);

Here 12 will be the maximum length of the random number .


Regards

Joshi.

[redarrow]

joshi_v that a bit stupis to md5 a refrence number any reason why cheers.

[xsist10]

[code]
<?php
echo getrandmax();
?>
[/code]

Random numbers only go up to 2147483647.
You're working with integers remember. Once it passes 2147483647 it will become -2147483648 and then -2147483647 and cycle back to 0 again.

[Xurion]

joshi_v's example comes back with an alphanumerical string like 58ab75d79013.

Decided to go with this:

[code]$ordernumber = ceil(rand(100000, 999999)).''.ceil(rand(100000, 999999));[/code]

Thx all

[Daniel0]

[code]<?php
for($i=1;$i<=12;$i++)
{
$num .= chr(rand(48,57));
}

echo $num;
?>[/code]