Javascript 解构可能返回未定义的函数的返回

我有以下代码

App.tsx

  const handleKeyDown = ({key}: {key: string}) => {

    const [newDirection, nextWalkingState, newPosition] = handleDogMovement(key, dogObject, invalidPositionsTest);
  }

export const handleDogMovement = (key: string, dogObject : Tile, invalidPositions : Position[]) => {
  const newDirection = mapKeyDownToDirectionImpl[key.toLowerCase()];
  if (!newDirection) return;

  const {direction, walkingState, pos} = dogObject;
  const nextWalkingState = newDirection === direction ? walkingState! + 2 : 2;
  const {offsetX, offsetY} = mapDirectionToOffset[newDirection];
  const newPosition = {x: pos.x + offsetX, y: pos.y + offsetY}
  if (!isNewPositionValid(newPosition, invalidPositions)) return;
  return [newDirection, nextWalkingState, newPosition];
}

---

然而，handleDogMovement可能返回未定义的。我还能这样分解结果吗？

你不能；它会抛出一个错误。试试这个：

const[newDirection，nextWalkingState，newPosition]=handleDogMovement（键，dogObject，invalidPositionTest）| |[]；

现在，如果函数返回

undefined

，那么变量将是

undefined

，但至少不会使脚本崩溃