我想声明类中对象的值，并且仅在Im声明新类时调用键。我该怎么办？

Question

这就是我到目前为止所做的。

class PriceCalc {

  constructor(Obj) {

    this.parts = Object.keys(Obj);

    this.cost =

      "$" +

      Object.values(Obj)

        .reduce((a, b) => a + b, 0)

        .toFixed(2);

    this.retail =

      "$" +

      (

        Object.values(Obj).reduce((a, b) => a + b, 0) +

        Object.values(Obj).reduce((a, b) => a + b, 0) * 1.75

      ).toFixed(2);

    this.quote = qt + this.retail;

  }

}

var total = new PriceCalc({

  Motherboard: 520.99,

  RAM: 250.4,

  SSD: 500.8,

  HDD: 400.66,

  Case: 375.5,

  Monitor: 600.75,

  Keyboard: 100.99,

  Mouse: 25.5

});

console.log(total.parts);

console.log(total.cost);

console.log(total.retail);

console.log(total.quote);

Id想要实现的是将值声明在类中，然后只调用类似的东西

var total = new PriceCalc({Motherboard, RAM, SSD, HDD});

并返回指定部件的组合值，在本例中为 $1，672.85，对于此.cost

Answer 1

将默认值放入类属性。传递要获取的属性字符串。用于获取对象属性this[b]确保你把数字而不是字符串相加：会给你字符串串联而不是算术运算。qt + this.quoteclass PriceCalc {  Motherboard = 520.99;  RAM = 250.40;  SSD = 500.80;  HDD = 400.66;  Case = 375.50;  Monitor = 600.75;  Keyboard = 100.99;  Mouse = 25.50;    parts = []  cost = '$0'  retail = '$0'  quote = '0'  constructor(Obj) {    this.parts = Obj.join(',');    this.cost = "$" + (Obj.reduce((a, b) => a + this[b], 0).toFixed(2));    this.retail = "$" + ((Obj.reduce((a, b) => a + this[b], 0) + (Obj.reduce((a, b) => a + this[b], 0) * 1.75)).toFixed(2));    //this.quote = qt + this.retail;  }}var total = new PriceCalc([  'Motherboard',  'RAM',  'SSD',  'HDD']);console.log(total.parts)console.log(total.cost)console.log(total.retail)console.log(total.quote)