将数组中对象的所有值相加，但与数量相乘

const data = [
  { value: 10, quantity: 2 },
  { value: 20, quantity: 3 },
  { value: 30, quantity: 1 }
];

const total = data.reduce((accumulator, currentItem) => {
  return accumulator + (currentItem.value * currentItem.quantity);
}, 0);

console.log(total); // 输出: 110

const total = data.reduce((accumulator, currentItem) => {
  if (currentItem.value !== undefined && currentItem.quantity !== undefined) {
    return accumulator + (currentItem.value * currentItem.quantity);
  }
  return accumulator;
}, 0);

const total = data.reduce((accumulator, currentItem) => {
  if (typeof currentItem.value === 'number' && typeof currentItem.quantity === 'number') {
    return accumulator + (currentItem.value * currentItem.quantity);
  }
  return accumulator;
}, 0);