如何使用 array.filter 方法过滤单词答案

【问题标题】：How to filter a word using array.filter method如何使用 array.filter 方法过滤单词
【发布时间】：2021-05-05 15:38:38
【问题描述】：

我只是想知道如何使用过滤器方法返回 name 属性等于“Bob”的对象的索引。（在这种情况下，为简单起见一个索引）

数据.json

[
 {
    "index": "14",
    "name": "Bob",
    "age": "23",
  },
  {
    "index": "23",
    "name": "John",
    "age": "30",
  },
  {
    "index": "17",
    "name": "Bob",
    "age": "25",
  },
]

app.js

const data = require("./data.json");


const searchword = "Bob";
const result = data.filter((word) => ???word === searchword???);
console.log(result);

应该显示索引：14,17

【问题讨论】：

标签： javascript arrays filter properties

【解决方案1】：

这就像filter 和map 一样简单

const data = [
 {
    "index": "14",
    "name": "Bob",
    "age": "23",
  },
  {
    "index": "23",
    "name": "John",
    "age": "30",
  },
  {
    "index": "17",
    "name": "Bob",
    "age": "25",
  },
]

const searchWord = "Bob";
const result = data.filter(x => x.name == searchWord) // find by searchWord
                   .map(x => x.index); // get the index
console.log(result.join(",")); // result is an array

【讨论】：

【解决方案2】：

使用reduce方法

const data = [
  {
    index: "14",
    name: "Bob",
    age: "23",
  },
  {
    index: "23",
    name: "John",
    age: "30",
  },
  {
    index: "17",
    name: "Bob",
    age: "25",
  },
];

const getIndexes = (arr, word) =>
  arr.reduce(
    (acc, { index, name }) => (name === word ? acc.concat(index) : acc),
    []
  ).toString();

console.log(getIndexes(data, "Bob"));

【讨论】：