如何在laravel中使用php爆炸？

$user = $this->user;
            $user->name = $request['name'];
            $user->email = $request['email'];
            $user->password = $request['password'];
            $user->save();

$name = explode(' ',$user->name);

$profile= $user->userdetail()->create([
                'user_id' => $request->input('id'),'first_name' => <the value of the first exploded string>
'last_name' => the value of the secondexploded string
                ]);

            return redirect('confirmation');
        }

如何在php中使用explode函数拆分两个单词？例如,我注册了JOhn doe的名字我想在我的userdetail表中创建john的first_name和doe的last_name.我该怎么做/