Convert array keys from underscore_case to camelCase recursively

Question

I had to come up with a way to convert array keys using undescores (underscore_case) into camelCase. This had to be done recursively since I did not know what arrays will be

Answer 1

Here is another approach taking advantage of array_walk_recursive() and preg_replace_callback methods in the simplest possible way :)

function convertKeysToCamelCase($array)
{
    $result = [];

    array_walk_recursive($array, function ($value, &$key) use (&$result) {
        $newKey = preg_replace_callback('/_([a-z])/', function ($matches) {
            return strtoupper($matches[1]);
        }, $key);

        $result[$newKey] = $value;
    });

    return $result;
}