In PHP, how do you change the key of an array element?

Question

I have an associative array in the form key => value where key is a numerical value, however it is not a sequential numerical value. The key is actually an I

Answer 1

this works for renaming the first key:

$a = ['catine' => 'cat', 'canine'  => 'dog'];
$tmpa['feline'] = $a['catine'];
unset($a['catine']);
$a = $tmpa + $a;

then, print_r($a) renders a repaired in-order array:

Array
(
    [feline] => cat
    [canine] => dog
)

this works for renaming an arbitrary key:

$a = ['canine'  => 'dog', 'catine' => 'cat', 'porcine' => 'pig']
$af = array_flip($a)
$af['cat'] = 'feline';
$a = array_flip($af)

print_r($a)

Array
(
    [canine] => dog
    [feline] => cat
    [porcine] => pig
)

a generalized function:

function renameKey($oldkey, $newkey, $array) {
    $val = $array[$oldkey];
    $tmp_A = array_flip($array);
    $tmp_A[$val] = $newkey;

    return array_flip($tmp_A);
}