X Marks the Perfect Shot.js

const moves = ['north', 'north', 'west', 'west', 'north', 'east', 'north'];

const finalPosition = function (moves) {
  let x = 0;
  let y = 0;

  for (let move of moves) {
    switch (move) {
      case 'north':
        y++;
        break;
      case 'south':
        y--;
        break;
      case 'east':
        x++;
        break;
      case 'west':
        x--;
        break;
    }
  }

  return [x, y];
}

finalPosition(moves);