React中求和运算返回NaN的解决方案

const productsObj = [{
    id: 1,
    name: 'Sweater',
    size: 'M',
    gender: 'Men',
    price: 2300,
    printPrice: 180,
    minQuantity: 1,
    total: 2300,
  },
  {
    id: 2,
    name: 'Shirt',
    size: 'M',
    materijal: 'Pamuk',
    gender: 'Men',
    price: 1500,
    printPrice: 180,
    minQuantity: 1,
    total: 1500,
  }];

const [products, setProducts] = React.useState(productsObj);

//onChange on quantity input:
const handleQuantityChange = (e, id) => {
  setProducts(
    products.map((item) => {
      if (item.id === id) {
        const quantity = parseInt(e.target.value, 10); // 确保是数字类型
        const newTotal = item.price * quantity;
        return {
          ...item,
          quantity: quantity,
          total: newTotal,
        };
      } else {
        return item;
      }
    })
  );
};

//function that sums all the total's
const allTotal = () => {
  let sum = 0; // 初始化累加变量为0

  products.forEach((e) => {
    sum += e.total;
  });

  return sum;
};

const allTotal = () => {
  return products.reduce((sum, product) => sum + product.total, 0);
};