Probability Random Choice in PHP?

mohamad_1978

Hello Guys..

I am looking for a script or method that will pick an item from a list randomly.. But with each item having a certain "chance" of being chosen..

For example I want to pick one of those two (Cat or Dog) where Dog has a 70% chance of being chosen and Cat has a 30% chance.

I will need to repeat this method many many times in my program so please try to give me a method that is maximized and causes minimum load.

dalecosp

<?
$stuff=array('dog', 'cat', 'other');
$choice=choose($stuff, 70);
echo $stuff['choice'];

function choose($stuff, $prob1) {
   $chance=rand(1,100);
   if ($chance<=$prob1) { $a=0; }
   else { $a=1;}
   return $a;
   }
?>

Conversation starter, perhaps....

mohamad_1978

it is will if we have chose between 2 as i think but if we have more then 2
lets say

cat 30% .. dog 10% .. car 50% .. computer 10%

how can i do it

dalecosp

Extending the original function...

<?
$stuff=array('dog', 'cat', 'car', 'house', 'donut');
$choice=choose($stuff, 30,50,70,90,100);
echo $stuff[$choice];

function choose($stuff, $prob1, $prob2, $prob3, $prob4, $prob5) {
   $chance=rand(1,100);
   if ($chance<=$prob1) { $a=0; }
   elseif ($chance<=$prob2) { $a=1; }
   elseif ($chance<=$prob3) { $a=2; }
   elseif ($chance<=$prob4) { $a=3; }
   else { $a=4;}
   return $a;
   }
?>

There are quite possibly other ways, also. But I'm having trouble 'thinking outside the box' lately....