ループで連想配列からキーと値を取得する|PHP

$array = ['1' => 'ONE', '2' => 'TWO', '3' => 'THREE'];
$newArray = [];
foreach($array as $key => $value) {
    $newArray['code_' . $key] = $value;
}
print_r($newArray);

Array ( [code_1] => ONE [code_2] => TWO [code_3] => THREE )