如何访问 node.js 中的对象数据？ [复制]

Question

这是我的对象。

players:{
   "ssa": {
     "roomCode": "SJRJzaGA8",
     "imagesAlloted": [],
     "team": "",
     "sessionId": "0gSfuhvVF"
   },
   "ss": {
     "roomCode": "SJRJzaGA8",
     "imagesAlloted": [],
     "team": "",
     "sessionId": "8G7QtTEXV"
   }
}

我想用键和值迭代整个对象

我正在使用

for(let [key, value] in players){
   console.log(key + "has" + JSON.stringify(value));
}

这给出的输出类似于：

[0] "$" is "c"
[0] "$" is "i"
[0] "t" is "o"
[0] "c" is "l"
[0] "t" is "r"

我使用的是节点版本 16.13

Answer 1

使用Object.entries() 获取键和值。

Object.entries(players).forEach(([key, value]) => console.log(key + "has" + JSON.stringify(value)))

Answer 2

您可以使用Object.entries() 和flatMap()

const players = {
  "ssa": {
    "roomCode": "SJRJzaGA8",
    "imagesAlloted": [],
    "team": "",
    "sessionId": "0gSfuhvVF"
  },
  "ss": {
    "roomCode": "SJRJzaGA8",
    "imagesAlloted": [],
    "team": "",
    "sessionId": "8G7QtTEXV"
  }
}

const result = Object.values(players).flatMap((v) => {
    return Object.entries(v).flat();
});

console.log(result);

Answer 3

我会让我的 for 循环像这样

for (let player in players) {
  console.log("Key: ", player, " has ", players[player]);
}

player 是关键

players[player] 会给你那个玩家的价值。

你的方式

for (const [key, value] of Object.entries(object1)) {
  console.log("Key: ", key, " has ", value);
}

也应该给你同样的结果。这是 MDN 参考 https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries

Answer 4

此线程中提出的其他解决方案有效，但我觉得 OP 在他的 for/in 循环的语法上犯了一个基本错误，对他/她来说理解初始代码失败的原因很重要。这是因为[key, value] 周围不应该有括号。用 for/in 循环做 OP 想要的，语法是：

for(let p in players){
   console.log(p, players[p]);
}

输出：

ssa {roomCode: 'SJRJzaGA8', imagesAlloted: Array(0), team: '', sessionId: '0gSfuhvVF'}
ss {roomCode: 'SJRJzaGA8', imagesAlloted: Array(0), team: '', sessionId: '8G7QtTEXV'}

你得到单个字母的原因是你不正确的[key, value]片段是destructuring每个键。当您尝试将字符串解构为数组时，该字符串将分解为单个字符。因此，给定语句const [foo, bar, baz] = "ABC" 会将 A 分配给 foo，B 分配给 bar，依此类推。您的原始代码遍历对象，将每个键作为字符串提取，将该字符串的第一个和第二个字母分配给变量，然后记录变量。