discord.js：将存储为json文件的数组内容随机化

Question

I'm working on a small Discord bot to try and teach myself a bit of js, but I've run into something I can't really work out or find an answer to.

I have a command that has the bot post a quote at random from an array stored in a separate json file, and this works as intended.

var config = require("./settings.json");
var quotes = config.quotes;

function randomQuote() {
   return quotes[Math.floor(Math.random() * quotes.length)];
};

if(message.content.toLowerCase() === prefix + "quote") {
   message.channel.send(randomQuote());
}

I'm now trying to do something similar, except rather than the array being a part of the json file, it is the json file. Essentially, the user can tell the bot to save a certain message, and it takes the message author & content and adds them as an entry to the array. It should then do the same as the quote function, randomise the entries in the array and then print one into the chat.

var mess;

let saveMess = JSON.parse(fs.readFileSync("./saveMess.json", "utf8"));

function randomMess() {
    return saveMess[Math.floor(Math.random() * saveMess.length)];
};

if(message.content.toLowerCase().startsWith(prefix + "saveMess")) {
    mess = message.author + " told me the following:\n" + message.content;
    fs.readFile("./saveMess.json", function (err, data) {
        var json = JSON.parse(data)
        json.push(mess)
        fs.writeFile("./saveMess.json", JSON.stringify(json), (err) => {
            if (err) console.error(err)
        });
    })
}

if(message.content.toLowerCase() === prefix + "printMess") {
    message.channel.send(randomMess());
}

From my testing, I know it's being correctly stored in an array, and asking to print the entire file correctly (ie message.channel.send(saveMess) ) displays all the saved entries; however, when attempting to do the same randomising function, I get the error "cannot send empty message". Clearly, there's something I'm missing that sets an array contained within a json file apart from an array that is a json file; does anyone have any ideas on how I can get this working as intended?

For clarification, here's how the two json files look, to demonstrate the difference I'm talking about:

//settings.json - the quote file

{ "token" : "BotTokenHere",
    "prefix" : "|",
    "quotes" : [
        "Quote 1",
        "Quote 2",
        "Quote 3"
    ]
}

---

//savemess.json - the saved messages file

[
    "<@user1> told me the following:\n|saveMess test",
    "<@user2> told me the following:\n|saveMess test2",
    "<@user3> told me the following:\n|saveMess test3"
]

Answer 1

According to the JSON guidelines at json.org , a json file must be an object, it cannot be an array. It is possible that JSON.parse is not throwing an error, however returning an empty array/object. You should stick with using the original settings.json .