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cam · 07-01-2005, 10:29

Trying to sort an array pseudo-randomly by feeding a pseudo-random seed to a function.

Basically, need to "randomize" a result set but need to be able to reconstruct that result set in the same order sometime in the future.

Already know how to generate random seeds, any ideas as to the sorting with a seed?

---

just to clarify:

array ( 1, 2, 3, 4, 5 )

Bob visits the site and gets the result set: 3,4,1,2,5

next time bob visits he gets 3,4,1,2,5 again.

stickmus · 10-01-2005, 05:39

You'll be needing the srand function

like this

PHP Code:


		
			
<?php

function do_seed() {

    if (!($seed = $_GET['seed'])) $seed = 0;

    srand($seed);

}

?>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />

<title>Untitled Document</title>

</head>



<body>

<? 

do_seed();

$myarray = array (1, 2, 3, 4, 5);

shuffle($myarray);

?>

<form action="<? print $_SERVER['PHP_SELF']; ?>" method="get">

    <label for="seed">Seed</label><br />

    <input type="text" name="seed" id="seed" value="<? print $_GET['seed'] ?>"/><br />

    <input type="submit" value="seed array"/>

</form>

<pre>

<?

print_r($myarray);

?>

</pre>

</body>

</html>

See it here: http://www.gsgd.co.uk/xhtml/rand_array.php

cam · 10-01-2005, 06:00

Ahh, i'd taken the notes on that being deprecated as meaning it can no longer be used but of course it can. Cheers stickmus, that's awesome

stickmus · 10-01-2005, 06:23

Not deprecated, you just don't need to use it unless you do, if you see what i mean.

07-01-2005, 10:29	#1 (permalink)
cam vague™ Join Date: Mar 2004 Location: Glasgow Posts: 5,595	php random array sorting Trying to sort an array pseudo-randomly by feeding a pseudo-random seed to a function. Basically, need to "randomize" a result set but need to be able to reconstruct that result set in the same order sometime in the future. Already know how to generate random seeds, any ideas as to the sorting with a seed? --- just to clarify: array ( 1, 2, 3, 4, 5 ) Bob visits the site and gets the result set: 3,4,1,2,5 next time bob visits he gets 3,4,1,2,5 again. __________________ The Blog™ \| TWHF \| Twitter \| LinkedIn Last edited by i_am_cam : 07-01-2005 at 10:39.

10-01-2005, 05:39	#2 (permalink)
stickmus hmmm... Join Date: Jan 2004 Location: Yorkuk Posts: 2,127	You'll be needing the srand function like this PHP Code: <?php function do_seed() { if (!($seed = $_GET['seed'])) $seed = 0; srand($seed); } ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> <title>Untitled Document</title> </head> <body> <? do_seed(); $myarray = array (1, 2, 3, 4, 5); shuffle($myarray); ?> <form action="<? print $_SERVER['PHP_SELF']; ?>" method="get"> <label for="seed">Seed</label><br /> <input type="text" name="seed" id="seed" value="<? print $_GET['seed'] ?>"/><br /> <input type="submit" value="seed array"/> </form> <pre> <? print_r($myarray); ?> </pre> </body> </html> See it here: http://www.gsgd.co.uk/xhtml/rand_array.php

10-01-2005, 06:00	#3 (permalink)
cam vague™ Join Date: Mar 2004 Location: Glasgow Posts: 5,595	Ahh, i'd taken the notes on that being deprecated as meaning it can no longer be used but of course it can. Cheers stickmus, that's awesome __________________ The Blog™ \| TWHF \| Twitter \| LinkedIn

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10-01-2005, 06:23	#4 (permalink)
stickmus hmmm... Join Date: Jan 2004 Location: Yorkuk Posts: 2,127	Not deprecated, you just don't need to use it unless you do, if you see what i mean.

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