Alt-PHP-Faq
Cheapest CO.UK domains in the UK! £1.88 per year!
And PHP/MySQL hosting 1p/1c for the first month, NO CATCH!


Question :

Why doesn't rand give random numbers?

Answer :
I use the following code

$iRandom = rand(0,100);

But I dotn get random numbers, whats wrong?

You have not RTFM'ed good enough, if you read the man page for rand carefully you will find a line that states:

"Remember to seed the random number generator before use with srand()."

So the proper code would be:

srand((double)microtime()*1000000); 
$iRandom = rand(0,100);


As an alternative you can use mt_rand which should generate more random, numbers. Read more about that here:
http://www.php.net/manual/en/function.mt-rand.php



Categories Return to Main PHP Faq

General

 

Questions

General
How do I run a php script from the command line?
What does PHP stand for?
Can I connect to a Microsoft Access database without a DSN?
How can I set the include path and other settings that are fixed in php.ini without having access to php.ini?
Can I get the screen resolution and like with php?
Whats the difference between include() and require()?
How can I convert a Access database to a MySQL database?
I am totally new to PHP / MySQL / Programming in General. Where is a good place to start learning?
How do I get the visitors browser information?
How do I send mails with PHP?
Are there any good PHP development environments / editors for Windows?
Can I use php with cron on unix systems?
What is PEAR?
Can php and flash work together?
How can I develop my own PHP extension ?
Have you read this article, "Student Suspended Over Suspected Use of PHP"?
Using Apache can I get php to parse files not ending in .php?
How do I get started to use php?
How do I find out how a user came to my page?
How can I send large amounts of emails with php?
Why do I get "Warning: open(/tmp\sess_03416739e8d8712a1489aa6bb6bdf19d, O_RDWR)" failed ?
Where can I get a php mode for emacs?
Are there any good PHP development environments / editors for Linux?
Why do i get the error "Cannot add header information" ?
What does it mean when there is a & infront of a variable?
I get an error 'PDF_set_info' must not be called in 'object' scope in script.php on line xxx
How do I turn newlines / returns into html breaks (<br>)?
Where can I get a copy of PHP?
I am using PHP with SQL - can I ask a question in alt.php?
How do I find out what mode to use when creating dirs with mkdir
Who do I contact to add to this faq?
How can I redirect all http (non-secure port 80) requests to https (Secure port 443)
 

Return to the main FAQ list



Free Forum    
Design & Layout Copyright © 2000- 2008 PHP MySQL Web Hosting Comments to Webmaster
Hosted by PHP 4 Hosting - PHP and MySQL Webhosting and Domain Names