Variable inside Module keeps on returning undefined-CodePudding

I want to modify variable currentPlayer each turn. I have added PlayerController.switchPlayer() to an event listener as well. But every time currentPlayer fails to get updated and returns undefined. I even tried moving the same variable to global as an undefined and still it will fail to get updated despite the code running through the whole if/else block.

const PlayerController = (() => {
  let playerO = Player("O");
  let playerX = Player("X");
  let currentPlayer;
  let switchPlayer = () => {
    if (!playerO.activePlayer) {
      playerO.activePlayer = true;
      playerX.activePlayer = false;
      currentPlayer = playerO;
    } else if (playerO.activePlayer && !playerX.activePlayer) {
      playerX.activePlayer = true;
      playerO.activePlayer = false;
      currentPlayer = playerX;
    }
  };
  return { playerO, playerX, switchPlayer, currentPlayer };
})();

CodePudding user response：

The object to be returned is calculated once - at the end of the IIFE. Calling switchPlayer and reassigning the local currentPlayer does not change the returned object with the currentPlayer property, because the object has already been evaluated and returned.

You could make currentPlayer into a getter instead, so that it returns the possibly-reassigned value inside the IIFE:

return {
  playerO,
  playerX,
  switchPlayer,
  get currentPlayer() {
    return currentPlayer;
  }
};

But I'd prefer to not hide the fact that it's a function, so that you call getCurrentPlayer from the outside.

return {
  playerO,
  playerX,
  switchPlayer,
  getCurrentPlayer: () => currentPlayer
};