note 83358 added to function.mt-rand

Here is a simple way to get UNIQUE random numbers, because if you are wanting random numbers, say, between 1 and 10, then you will get duplicates very often, so this function takes care of that. However, for a very large amount of numbers, this could be very slow. I use this to generate random pictures on a webpage so that I don't get the same picture twice, but it only picks from about 50 pictures. // ************************************************** // generate UNIQUE random numbers between min and max // uses the updated mt_rand() php function // 'min' = minimum random number // 'max' = maximum random number // 'count' = how many numbers in the array // returns array with random numbers // error msg if count is greater than max // ************************************************** function generateUniqueRandoms($min, $max, $count) { if($count > $max) { // this prevents an infinite loop echo "ERROR: The array count is greater than the random number maximum.<br>\n"; echo "Therefore, it is impossible to build an array of unique random numbers.<br>\n"; break; } $numArray = array(); for($i = 0; $i < $count; $i++) { $numArray[$i] = mt_rand($min,$max); // set random number for($j = 0; $j < $count; $j++) // for each number, check for duplicates if($j != $i) // except for the one you are checking of course if($numArray[$i] == $numArray[$j]) { $numArray[$i] = mt_rand(1,10); // if duplicate, generate new random $j = 0; // go back through and check new number } } return $numArray; } // end generateUniqueRandoms() ---------------------- // **************************************************** ---- Server IP: 64.71.164.2 Probable Submitter: 68.47.206.149 ---- Manual Page -- http://www.php.net/manual/en/function.mt-rand.php Edit -- https://master.php.net/note/edit/83358 Del: integrated -- https://master.php.net/note/delete/83358/integrated Del: useless -- https://master.php.net/note/delete/83358/useless Del: bad code -- https://master.php.net/note/delete/83358/bad+code Del: spam -- https://master.php.net/note/delete/83358/spam Del: non-english -- https://master.php.net/note/delete/83358/non-english Del: in docs -- https://master.php.net/note/delete/83358/in+docs Del: other reasons-- https://master.php.net/note/delete/83358 Reject -- https://master.php.net/note/reject/83358 Search -- https://master.php.net/manage/user-notes.php