// unique() forces providers to return unique values $values = []; for ($i = 0; $i < 10; $i++) { // get a random digit, but always a new one, to avoid duplicates $values []= $faker->unique()->randomDigit(); } print_r($values); // [4, 1, 8, 5, 0, 2, 6, 9, 7, 3] // providers with a limited range will throw an exception when no new unique value can be generated $values = []; try { for ($i = 0; $i < 10; $i++) { $values []= $faker->unique()->randomDigitNotNull(); } } catch (\OverflowException $e) { echo "There are only 9 unique digits not null, Faker can't generate 10 of them!"; } // you can reset the unique modifier for all providers by passing true as first argument $faker->unique($reset = true)->randomDigitNotNull(); // will not throw OverflowException since unique() was reset // tip: unique() keeps one array of values per provider // optional() sometimes bypasses the provider to return a default value instead (which defaults to NULL) $values = []; for ($i = 0; $i < 10; $i++) { // get a random digit, but also null sometimes $values []= $faker->optional()->randomDigit(); } print_r($values); // [1, 4, null, 9, 5, null, null, 4, 6, null] // optional() accepts a weight argument to specify the probability of receiving the default value. // 0 will always return the default value; 1.0 will always return the provider. Default weight is 0.5 (50% chance). // Please note that the weight can be provided as float (0 / 1.0) or int (0 / 100) // As float $faker->optional($weight = 0.1)->randomDigit(); // 90% chance of NULL $faker->optional($weight = 0.9)->randomDigit(); // 10% chance of NULL // As int $faker->optional($weight = 10)->randomDigit; // 90% chance of NULL $faker->optional($weight = 100)->randomDigit; // 0% chance of NULL // optional() accepts a default argument to specify the default value to return. // Defaults to NULL. $faker->optional($weight = 0.5, $default = false)->randomDigit(); // 50% chance of FALSE $faker->optional($weight = 0.9, $default = 'abc')->word(); // 10% chance of 'abc' // valid() only accepts valid values according to the passed validator functions $values = []; $evenValidator = function($digit) { return $digit % 2 === 0; }; for ($i = 0; $i < 10; $i++) { $values []= $faker->valid($evenValidator)->randomDigit(); } print_r($values); // [0, 4, 8, 4, 2, 6, 0, 8, 8, 6] // just like unique(), valid() throws an overflow exception when it can't generate a valid value $values = []; try { $faker->valid($evenValidator)->randomElement([1, 3, 5, 7, 9]); } catch (\OverflowException $e) { echo "Can't pick an even number in that set!"; }