javascript - 如何从node.js调用JSON中的数组字段

Question

在 node.js 应用程序中，在 server.js 文件中，我尝试使用以下代码从名为 Deckofcardsapi 的外部 api 发出请求并将值打印到控制台。

const  request = require('request');
request('https://deckofcardsapi.com/api/deck/new/draw/?count=2', function (error, response, body) {
const data = JSON.parse(body);
console.log('remaining :', data.remaining);
console.log('statusCode:', response && response.statusCode);
console.log('suit:', data.cards[suit]);
});

当我尝试data.cards[suit]时，我收到如下错误。

console.log('suit:', data.cards[suit]);
ReferenceError: suit is not defined
at Request._callback (/Users/lokanathc/Projects/deckOfCards/server.js:48:37)
at Request.self.callback (/Users/lokanathc/Projects/deckOfCards/node_modules/request/request.js:185:22)
at emitTwo (events.js:126:13)
at Request.emit (events.js:214:7)
at Request.<anonymous> (/Users/lokanathc/Projects/deckOfCards/node_modules/request/request.js:1161:10)
at emitOne (events.js:116:13)
at Request.emit (events.js:211:7)
at IncomingMessage.<anonymous> (/Users/lokanathc/Projects/deckOfCards/node_modules/request/request.js:1083:12)
at Object.onceWrapper (events.js:313:30)
at emitNone (events.js:111:20)`

但是当我只使用data.cards时，我得到以下输出

remaining : 50
statusCode: 200
suit: [ { code: 'QC',
images:
 { png: 'https://deckofcardsapi.com/static/img/QC.png',
   svg: 'https://deckofcardsapi.com/static/img/QC.svg' },
value: 'QUEEN',
image: 'https://deckofcardsapi.com/static/img/QC.png',
suit: 'CLUBS' },
  { code: '5S',
images:
 { png: 'https://deckofcardsapi.com/static/img/5S.png',
   svg: 'https://deckofcardsapi.com/static/img/5S.svg' },
value: '5',
image: 'https://deckofcardsapi.com/static/img/5S.png',
suit: 'SPADES' } ]

我应该使用什么来访问suit: 'SPADES'的值。

这是来自 API 的以下响应。

{
"success": true,
"cards": [
    {
        "image": "https://deckofcardsapi.com/static/img/KH.png",
        "value": "KING",
        "suit": "HEARTS",
        "code": "KH"
    },
    {
        "image": "https://deckofcardsapi.com/static/img/8C.png",
        "value": "8",
        "suit": "CLUBS",
        "code": "8C"
    }
],
"deck_id":"3p40paa87x90",
"remaining": 50
}

Answer 1

您应该使用过滤方法，例如: data.cards.filter(card => card.suit == 'SPADES');

Documentation of filter method

编辑:

如果您想访问对象数组中 suit 的所有值:

让 suites = data.cards.map(card => card.suit);//套件是 ['SPADES','HEARTS']