PHP - Generate all combinations of items in array

Question

I have a PHP array like this...

$myarray = array(
\'red\', \'yellow\', \'green, \'blue\'
);

Order does not matter to me so I think I am trying

Answer 1

This example below

 $myarray = array( 'red', 'yellow', 'green', 'blue' );
 $finalarray = [];
 for ($i = 0; $i < count($myarray); $i++) {
     for ($j = $i + 1; $j < count($myarray); $j++) {
         $finalarray[] = $myarray[$i];
         $finalarray[] = $myarray[$j];
     }
 }
 print_r($finalarray);

will print this

 Array ( [0] => red [1] => yellow [2] => red [3] => green [4] => red [5] => blue [6] => yellow [7] => green [8] => yellow [9] => blue [10] => green [11] => blue )