Why is Null returned?

Question

PHP

the code itself:

public function add($name, $method)
    {
        $func = $this->{$name};
        if(!isset($func))
        {
            $this->{$name} = $method;
        }
        return true;
    }

calling

$context->add("getUser", function () use ($vk) {
        return $vk->api->request("users.get", [])[0]["first_name"];
    });

server returns

Fatal error: Call to a member function add() on null in

Answer 1

The error message says that you are trying to call the add method on null, which means that your $context variable contains null. It is not possible to name the reason for this code.