如何从 JavaScript 中的对象数组中选择属性？

Question

我有这个代码：const arraySalesperson = ["John", "Alice", "Bob", "John", "John", "Alice"];const arraySales = [100, 420, 138, 89, 74, 86];const arrayGoals = [1, 2, 3, 4, 5, 6];// create a mapconst resultsBySalesperson = new Map();// traverse the list of salespersonsfor (let i = 0; i < arraySalesperson.length; i++) {  const name = arraySalesperson[i];    // see if it already exists in the map  let salesperson = resultsBySalesperson.get(name);  if (!salesperson) {    // if not, let's create an object now    salesperson = {      name: name,      sales: 0,      goals: 0    };    // store it in the map    resultsBySalesperson.set(name, salesperson);  }  // update the object  salesperson.sales += arraySales[i];  salesperson.goals += arrayGoals[i];}// here you have the map ready with both sales and goal properly accumulatedconsole.info([...resultsBySalesperson.entries()]);我需要使用属性 salesperson.sales 和 salesperson.goals。我该如何选择这些属性？我试过使用：resultsBySalesperson.get(name)resultsBySalesperson.get(salesperson.sales)resultsBySalesperson.get(salesperson.goals)但我觉得我做错了什么

Answer 1

您确实需要Map.get按姓名检索销售人员，但随后它会返回一个纯 JavaScript 对象，您可以使用点表示法访问其属性。

例如：

const resultsBySalesperson = new Map([

  [

    "John",

    {

      "name": "John",

      "sales": 263,

      "goals": 10

    }

  ],

  [

    "Alice",

    {

      "name": "Alice",

      "sales": 506,

      "goals": 8

    }

  ]

]);

const john = resultsBySalesperson.get("John");

console.log(john.sales);

console.log(john.goals);

或者，您也可以使用括号表示法（例如，john["sales"]）。

Answer 2

您可以使用解构赋值来获取所需的属性：

const {sales, goals} = resultsBySalesperson.get(name);

Answer 3

只需获取对象，然后获取想要的属性

person = resultsBySalesperson.get(name);

sales = person.sales;

goals = person.goals;