Vue计算属性默认值问题 选择的时候是正确的 不选的时候让他返回0 他却返回NAN

Question

computed: {

cartPrice() {
   let tmp = 0
   let tmpArr =[]
  if (this.goodsList.length) {
    tmpArr = this.goodsList.map(value => value.isChecked==true && value)
    tmpArr.forEach(value => (tmp += value.count * value.PRESENT_PRICE))
  }

  return tmp;
}

}

Answer 1

const list1 = [
  { goods: 'A', count: 2, PRESENT_PRICE: 3, isChecked: true },
  { goods: 'B', count: 3, PRESENT_PRICE: 1, isChecked: false },
  { goods: 'C', count: 0, PRESENT_PRICE: 3, isChecked: false },
  { goods: 'D', count: 4, PRESENT_PRICE: 5, isChecked: true }
];

const list2 = [
  { goods: 'A', count: 2, PRESENT_PRICE: 3, isChecked: false },
  { goods: 'B', count: 3, PRESENT_PRICE: 1, isChecked: false },
  { goods: 'C', count: 0, PRESENT_PRICE: 3, isChecked: false },
  { goods: 'D', count: 4, PRESENT_PRICE: 5, isChecked: false }
];

const list3 = [];

function getFinalPrice (cartList) {
  if (!cartList) return 0;

  return cartList
          .filter(item => item.isChecked && item.count)
          .reduce((total, item) => total + item.count * item.PRESENT_PRICE, 0);
}

console.log(getFinalPrice(list1));
console.log(getFinalPrice(list2));
console.log(getFinalPrice(list3));

在 DevTools 里检查一下数据类型

Answer 2

其实 return tmp || 0 这样就行了~~ 我是猪- -

Answer 3

条件判断语句不准确
false && item 返回的是 false 呀
把 map 换成 filter