combining two arrays using other methods other than array_splice

maryyyyyyy :

So I have two sets of arrays:

$a = [
    [
      'position' => 0,
      'color'    => 'violet'
    ],
    [
      'position' => 2,
      'color'    => 'red'
    ],
    [
      'position' => 5,
      'color'    => 'green'
    ],
];

$b = [
    [
      'color' => 'yellow'
    ],
    [
      'color' => 'orange'
    ],
    [
      'color' => 'pink'
    ],
    [
      'color' => 'blue'
    ],
];

And what I want to display from this is something like this:

array(7) {
  [0]=>
  array(1) {
    ["color"]=>
    string(6) "violet"
  }
  [1]=>
  array(1) {
    ["color"]=>
    string(6) "yellow"
  }
  [2]=>
  array(1) {
    ["color"]=>
    string(3) "red"
  }
  [3]=>
  array(1) {
    ["color"]=>
    string(6) "orange"
  }
  [4]=>
  array(1) {
    ["color"]=>
    string(4) "pink"
  }
  [5]=>
  array(1) {
    ["color"]=>
    string(5) "green"
  }
  [6]=>
  array(1) {
    ["color"]=>
    string(4) "blue"
  }
}

I'm currently using array_splice and it does work but it is very slow whenever there's a lot of data.
array_splice method:

foreach($a as $val) {
    array_splice($b, (int) $val['position'], 0, [['color' => $val['color']]]);
}

So what I want to ask is, is there like a PHP function for this or any other ways just to make it fast?

Any help or suggestions would be appreciated!

Thanks!

Andreas :

This method uses $a to get a "start" with array_column to get [pos => color].

Then I loop this array to see if there is a missing key, if there is a missing key add one item from $b, else reformat the array from [post => color] to [['color' => color]]

$pos = array_column($a, "color", "position");

$count = count($pos) + count($b);

for($i=0; $i<$count-1; $i++){
    if(!isset($pos[$i])){
        $pos[$i] = array_splice($b, 0, 1);
    }else{
        $pos[$i] = [$pos[$i]];
    }
}
ksort($pos);

var_dump($pos);

Same code but without array_splice.
Using a counter to know what item to pick from $b.

$pos = array_column($a, "color", "position");

$count = count($pos) + count($b);
$j = 0;

for($i=0; $i<$count-1; $i++){
    if(!isset($pos[$i])){
        $pos[$i] = $b[$j];
        $j++;
    }else{
        $pos[$i] = [$pos[$i]];
    }
}
ksort($pos);

var_dump($pos);

https://3v4l.org/3uPM3

But this requires $b to be indexed.