使用 Node 或 ES6 从 JSON 中过滤记录

Posted 2023-02-22

【中文标题】使用 Node 或 ES6 从 JSON 中过滤记录

【英文标题】：Filter Records from JSON with Node or ES6

【发布时间】：2016-10-14 15:36:42

【问题描述】：

我不确定解决此问题的最佳方法。例如，我想迭代我的json 并查找所有在美国的公司。随着我的应用程序的增长，这个JSON 可能会变得更加复杂，例如在关卡、对象等方面。我只想知道人们使用JSON 和Node.js 过滤掉数据子集的简单搜索和/或ES6 或库，例如Lodash 等。

例如这个 json，我有什么方法可以搜索它并只撤回美国的那些公司？

[
    "id": 0,
    "name": "Company1",
    "logoUrl": "/lib/assets/company1-logo.png",
    "location":
      "country": "USA",
      "state": "California",
      "city": "Napa"
    ,
    "active": false
  ,
  
    "id": 1,
    "name": "Company2",
    "logoUrl": "/lib/assets/company2-logo.png",
    "location":
      "country": "Germany",
      "state": "",
      "city": "Berlin"
    ,
    "active": false
  ,
  
    "id": 2,
    "name": "Company3",
    "logoUrl": "/lib/assets/company3-logo.png",
    "location":
      "country": "USA",
      "state": "Michigan",
      "city": "Detroit"
    ,
    "active": false
  ]

【问题讨论】：

是的，我知道，但你可以在没有 ES6 的情况下使用节点，我只是说如果你愿意，请使用 ES6，无论哪种方式都没有关系，只是想办法过滤这个

换句话说使用节点中间件来帮助过滤，或者使用普通的JS方法，或者使用你想要的任何想法或建议使用花哨的ES6

【参考方案1】：

您可以使用原生过滤功能。

const items = [
    "id": 0,
    "name": "Company1",
    "logoUrl": "/lib/assets/company1-logo.png",
    "location":
      "country": "USA",
      "state": "California",
      "city": "Napa"
    ,
    "active": false
  ,
  
    "id": 1,
    "name": "Company2",
    "logoUrl": "/lib/assets/company2-logo.png",
    "location":
      "country": "Germany",
      "state": "",
      "city": "Berlin"
    ,
    "active": false
  ,
  
    "id": 2,
    "name": "Company3",
    "logoUrl": "/lib/assets/company3-logo.png",
    "location":
      "country": "USA",
      "state": "Michigan",
      "city": "Detroit"
    ,
    "active": false
  ]

const usItems = items.filter(v => v.location.country === 'USA')

【参考方案2】：

您可以使用 javascript 的简单 .filter() 方法返回满足过滤器的结果列表。假设您的数据在可变数据中

ES5

data.filter(function(item) 
  return item.location.country === 'USA';
);

ES6：在 ES6 中，您可以使用箭头函数与

data.filter((item) => 
  return item.location.country === 'USA';
);

var data = [
    "id": 0,
    "name": "Company1",
    "logoUrl": "/lib/assets/company1-logo.png",
    "location":
      "country": "USA",
      "state": "California",
      "city": "Napa"
    ,
    "active": false
  ,
  
    "id": 1,
    "name": "Company2",
    "logoUrl": "/lib/assets/company2-logo.png",
    "location":
      "country": "Germany",
      "state": "",
      "city": "Berlin"
    ,
    "active": false
  ,
  
    "id": 2,
    "name": "Company3",
    "logoUrl": "/lib/assets/company3-logo.png",
    "location":
      "country": "USA",
      "state": "Michigan",
      "city": "Detroit"
    ,
    "active": false
  ];

var res1 = data.filter(function(item) 
  return item.location.country === 'USA';
);

const res2 = data.filter((item) => 
  return item.location.country === 'USA';
);

console.log(res1);
console.log(res2);

【参考方案3】：

在lodash中会是

_.filter(data, function(item) 
  return item.location.country === 'USA';
);

【参考方案4】：

使用 JavaScript 原生 Array#filter 方法和 ES6 arrow function

var res = data.filter(v => v.location.country === 'USA');

var data = [
  "id": 0,
  "name": "Company1",
  "logoUrl": "/lib/assets/company1-logo.png",
  "location": 
    "country": "USA",
    "state": "California",
    "city": "Napa"
  ,
  "active": false
, 
  "id": 1,
  "name": "Company2",
  "logoUrl": "/lib/assets/company2-logo.png",
  "location": 
    "country": "Germany",
    "state": "",
    "city": "Berlin"
  ,
  "active": false
, 
  "id": 2,
  "name": "Company3",
  "logoUrl": "/lib/assets/company3-logo.png",
  "location": 
    "country": "USA",
    "state": "Michigan",
    "city": "Detroit"
  ,
  "active": false
];

var res = data.filter(v => v.location.country === 'USA');

console.log(res);

【讨论】：

该死的，这比我想象的要容易