如何从JSON文件访问用户选择的变量？（Node.js）

这里有一个交易：我试图从JSON文件中的一个变量获取数据，该变量的名称与另一个变量不同。基本上，我希望通过使用Bands替换M83来访问MusicJSON.Bands.M83.length，否则，我必须将JSON文件中的每个变量添加到我的代码中，这对我来说是没有用的。这是我的密码：

    for(i = 0; i < MusicJSON.Bands.Names.length; i++) {
            var Band = MusicJSON.Bands.Names[i]
            NextMessage += "\n " + Band + MusicJSON.Bands.length + "  songs"; // Right here
        }
        NextMessage += "**";
        message.channel.send(`Here's a list of bands available on this server: \n ${NextMessage}`)

---

我正努力得到你想要的。如果你的乐队是这样的：

{
  Names: ["1", "2", "3", "M83"],
  1: ["song1", "song2", "song3"],
  2: ["song1", "song2", "song3"],
  3: ["song1", "song2", "song3"],
  M83: ["Midnight City", "Wait", "Outro"]
}

MusicJSON.Bands = {
  M83: ["Midnight City", "Wait", "Outro"],
  "System Of A Down": ["Toxicity", "Chic 'N' Stu", "Chop Suey"]
}

var names = Object.keys(MusicJSON.Bands).sort(), //create and array with the keys and sort it
  next = "";

for (let band of names) {
  next += `\n${band}: ${MusicJSON.Bands[band].length} songs`;
}
next += "**";
message.channel.send(`Here's a list of bands available on this server:\n${next}`);

如果要获得每个乐队的长度，请尝试以下方法：

var next = "";
for (let name of MusicJSON.Bands.Names) { //automatically loop through the array
  let number = MusicJSON.Bands[name].length; //access the object like MusicJSON.Bands["M83"]
  next += `\n${name}: ${number} songs` //add the text
}
next += "**";
message.channel.send(`Here's a list of bands available on this server:\n${next}`);

此外，请记住，如果名称是对象中的关键点，则不需要存储它们，因为您可以像这样循环关键点：

{
  Names: ["1", "2", "3", "M83"],
  1: ["song1", "song2", "song3"],
  2: ["song1", "song2", "song3"],
  3: ["song1", "song2", "song3"],
  M83: ["Midnight City", "Wait", "Outro"]
}

MusicJSON.Bands = {
  M83: ["Midnight City", "Wait", "Outro"],
  "System Of A Down": ["Toxicity", "Chic 'N' Stu", "Chop Suey"]
}

var names = Object.keys(MusicJSON.Bands).sort(), //create and array with the keys and sort it
  next = "";

for (let band of names) {
  next += `\n${band}: ${MusicJSON.Bands[band].length} songs`;
}
next += "**";
message.channel.send(`Here's a list of bands available on this server:\n${next}`);

我希望这是你想做的事