Question

I have this array:

$numbers = array(1, 2, 3);

I can grab a random value from it like so:

$numbers[array_rand($numbers)];

But I need to come up with different random variations of these values. For example

1
13
123
3
32
12
3
12
13
231

etc...

As you can see a number can’t repeat more than once in each set, so we can’t have sets like:

113
232
33

etc...

How can this be done?

Answer 1

One possible solution is:

$number1 = array(1, 2, 3);
$number2 = array(1, 2, 3);
$number3 = array(1, 2, 3);

$loop = 10;
for($i=0;$i<$loop;$i++) {
  $bool1 = mt_rand(0, 1);
  $bool2 = mt_rand(0, 1);

  $randomNumber = $number1[array_rand($number1)];
  if($bool1)
    $randomNumber .= $number2[array_rand($number2)];
  if($bool2)
    $randomNumber .= $number3[array_rand($number3)];
  echo $randomNumber;
}

This both randomly decides to choose between 1-3 digits and can use the numbers 1-3 as many times as possible. Just change $loop to the amount of times you want to run the generator.

I also just realised you could simplify this further:

$numbers = array(1, 1, 1, 2, 2, 2, 3, 3, 3);

$limit = mt_rand(1, 3);
$keys = array_rand($numbers, $limit);
$number = "";
if($limit == 1)
  $number .= $numbers[$keys];
else {
  foreach ($keys as $value) {
    $number .= $numbers[$value];
  }
}  

Insert each number the maximum amount of times into the array you want it to appear in any number (maximum number of digits you want to generate). And randomly generate a number between 1-3 with mt_rand() to use as your array_rand() limit.