LeetCode 682. Baseball Game

const calPoints = function (ops) {
  const stack = [];
 
  ops.forEach((op) => {
    if (op === '+') {
      stack.push(stack[stack.length - 1] + stack[stack.length - 2]);
    } else if (op === 'D') {
      stack.push(2 * stack[stack.length - 1]);
    } else if (op === 'C') {
      stack.pop();
    } else {
      stack.push(parseInt(op));
    }
  });
 
  return stack.reduce((a, b) => a + b, 0);
};

const calPoints = function (ops) {
  return ops.reduce().reduce((a, b) => a + b, 0)
};

const calPoints = (ops) => ops.reduce().reduce((a, b) => a + b, 0);

const calPoints = function (ops) {
 
  return ops.reduce((arrayScore, token) => {
    if (token === '+') {
      arrayScore.push(arrayScore[arrayScore.length - 1] + arrayScore[arrayScore.length - 2]);
        return arrayScore
    } else if (token === 'D') {
      arrayScore.push(2 * arrayScore[arrayScore.length - 1]);
        return arrayScore
    } else if (token === 'C') {
      arrayScore.pop();
        return arrayScore
    } else {
      arrayScore.push(parseInt(token));
        return arrayScore
    }
  }, []).reduce((a, b) => a + b, 0);
};

const calPoints = function (ops) {
 
  return ops.reduce((arrayScore, token) => {
    if (token === '+') {
      arrayScore.push(arrayScore[arrayScore.length - 1] + arrayScore[arrayScore.length - 2]);
    } else if (token === 'D') {
      arrayScore.push(2 * arrayScore[arrayScore.length - 1]);
    } else if (token === 'C') {
      arrayScore.pop();
    } else {
      arrayScore.push(parseInt(token));
    }
      return arrayScore
  }, []).reduce((a, b) => a + b, 0);
};