php - Create nested array by array of keys

Question

I've some difficulties creating a nested array by array of keys and assigning a value for the last nested item.

For example, lets $value = 4; and $keys = ['a', 'b', 'c'];

The final result should be:

[
  'a' => [
    'b' => [
      'c' => 4
    ]
  ]
]

I've tried with a recursion, but without success. Any help would be greatly appreciated.

Answer 1

you don't need recursion, just do it from the right to left:

$a = $value;
for ($i = count($keys)-1; $i>=0; $i--) {
  $a = array($keys[$i] => $a);
}

or the even shorter version from @felipsmartins:

$a = $value;
foreach (array_reverse($keys) as $valueAsKey) $a = [$valueAsKey => $a];