- var_dump: documentation ( source)
- array_replace: documentation ( source)
<?php
$original = [
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1
];
$update = [
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_2_0
];
var_dump($original, $update, $original += $update, array_replace($original, $update));