For example:

class TestController extends Controller
{
    public function index() {
        $arr = [1,2];
        return json_encode($arr);
    } 
}

Is there any way to automatically perform the json_encode operation when returning without requiring each function to manually perform the json_encode operation?

Additional explanation: What I mean is that jsone_encode() does not need to be explicitly specified in the return line, which means that response()->json() in laravel is also explicitly specified. This method is not the result I want. .

Solved:
I didn’t read the document carefully.
Just return the array directly.
return $arr;
return json_encode($arr);
The difference is:
The Content-Type of the former’s http Response Headers is application/json
The latter’s http Response Headers are Content-Type is text/html;

For the client, pay attention to the difference here.