Kill and reply JSON with PHP

Question

My framework submits forms with a fixed concatenation stating the type of data, which validation it should pass, the field name relative to the table in the BD and the value, would be something like:

data[0][]company_razao_social::Empresa::company_name::text::undefined

There is a class that explodes the string and mounts an array to check:

  {
        $arr = [];
        $key = 0;
        //print_r($_POST);
        foreach ($POST['data'] as $row)
        {
            $data = $row[0];
            $EXP = explode('::', $data);
            $label = $EXP[0];
            $value = $EXP[1];
            $validation = $EXP[4];
            if ($label == 'password')
            {
                $arr[$key][$label] = sha1($value); 
            } else
            {
                $arr[$key][$label] = utf8_encode(\vidbModel\validate::get_rs($value,$validation));
            }
            $key += 1;
        }
        return $arr;
    }

This returns an array to me:

Whether it has been validated:

$data['company_razao_social'] = 'Valor do campo';

Or, if not:

$data['company_razao_social'] = 'O campo não foi validado (Aqui vem a resposta de não ter sido)';

The problem of this is dealing with the client which is the error when there is someone.

What I want is:

Kill the function, and return a json only with the error when the data does not pass the validation, instead of continuing and returning the whole form with all the errors that there were and having to handle all this client side.

//Dentro do loop para desconcatenar
{
    $arr[$key][$label] = utf8_encode(\vidbModel\validate::get($value,$validation));
    if($$arr[$key][$label] = 'Possui erro'){
        die('devolver um json aqui');
    }
}

That way, the answer doesn’t come from json, and I’m not being able to return json with die, there’s another way to kill the method and return ? .

Note: break does not work either.

Answer 1

A little confused, but I believe it would be something like:

//Dentro do loop para desconcatenar
{
    $arr[$key][$label] = utf8_encode(\vidbModel\validate::get($value,$validation));
    if($$arr[$key][$label] = 'Possui erro'){
        header('Content-Type: application/json');
        echo json_encode(["erro" => "Mensagem de erro"]);
        die();
    }
}

Thus, the function header sends the appropriate HTTP header indicating that the response will be a JSON, the echo sets the body of the HTTP response, using the function json_encode to simplify, and finally to die would kill the process, ending the execution.