event.cpp

bool keys[255];

// constructor
EventHandler::EventHandler()
{
  for(int i = 0; i < 255; i++)
    keys[i] = false;
}

EventHandler::keyPressed(unsigned char key)
{
  keys[key] = true;
}

EventHandler::keyReleased(unsigned char key)
{
  keys[key] = false;'
}

// in your update loop

void GameClass::updateEverythingLoop()
{
  bool* kh = eh->getKeys(); // returns a pointer to the keys, which you know is an array of size 255.
  
  if(kh[SDL_UP_ARROW])
    player->moveUp();
  elseif
}