Question

In my script I want to run certain code a certain percent of the time, I’ve looked around StackOverflow and found the code below. It runs the code 33% of the time, what do I need to modify to get it to run 55% and 70% of the time?

$max = 27;

for($i = 1; $i < $max; $i++){
if($i % 3 == 0){
        call_function_here();
    }
}

Answer 1

Easiest way is to use a random number generator and test that its result is less than (or greater than, doesn’t matter) the amount you’re targeting for.

function percentChance($chance){
  // Notice we go from 0-99 - therefore a 100% $chance is always larger
  $randPercent = mt_rand(0,99);
  return $chance > $randPercent;
}

...

if(percentChance(30)){
  // 30% of page loads will enter this block
}

if(percentChance(100)){
  // All page loads will enter this block
}

if(percentChance(0)){
  // No chance this block will ever be entered
}