get random value from a PHP array, but make it uni

Question

I want to select a random value from a array, but keep it unique as long as possible.

For example if I'm selecting a value 4 times from a array of 4 elements, the selected value should be random, but different every time.

If I'm selecting it 10 times from the same array of 4 elements, then obviously some values will be duplicated.

I have this right now, but I still get duplicate values, even if the loop is running 4 times:

$arr = $arr_history = ('abc', 'def', 'xyz', 'qqq');

for($i = 1; $i < 5; $i++){
  if(empty($arr_history)) $arr_history = $arr; 
  $selected = $arr_history[array_rand($arr_history, 1)];  
  unset($arr_history[$selected]); 
  // do something with $selected here...
}

Answer 1

key != value, use this:

$index = array_rand($arr_history, 1);
$selected = $arr_history[$index];  
unset($arr_history[$index]); 

Answer 2

Php has a native function called shuffle which you could use to randomly order the elements in the array. So what about this?

$arr = ('abc', 'def', 'xyz', 'qqq');

$random = shuffle($arr);

foreach($random as $number) {
    echo $number;
}