discord.js中的“未定义”错误，有人可以帮助我吗？

Question

I started making an RPG Game in Discord with discord.js , but I got an error. Here is my code and the error:

let exp = require("./exp.json");
let userEXP = exp[message.author.id].exp;

if (voidCost) {
    exp[message.author.id] = {
        exp: exp[message.author.id].exp - 1700
    }

    fs.writeFile("./exp.json", JSON.stringify(exp), (err) => {
        if (err) {
           console.log(err)
        }
    })
}

let Void = require(`./weapons/Void.json`);

if (voidAmt) {
    Void[message.author.id] = {
        Void: Void[message.author.id].Void + 3
    }

    fs.writeFile("./weapons/Void.json", JSON.stringify(Void), (err) => {
        if (err) {
            console.log(err)
        }
    })
}

if (!Void[message.author.id]) {
    Void[message.author.id] = {
        Void: 0
    }
}

The error:

(node:8632) UnhandledPromiseRejectionWarning: TypeError:
Cannot read property 'Void' of undefined` (referred to "Void[message.author.id].Void")

Can somebody help me? What does the error mean and how can I avoid it?

Answer 1

Try doing it like this:

let Void = require(`./weapons/Void.json`);

if (voidAmt) {
    if (!Void[message.author.id]) {
        Void[message.author.id] = {
            Void: 0
        }
    }

    Void[message.author.id] = {
        Void: Void[message.author.id].Void + 3
    }

    fs.writeFile("./weapons/Void.json", JSON.stringify(Void), (err) => {
        if (err) {
            console.log(err)
        }
    })
}

So basically just move the check up.

Just saying using JSON for a Database is not very reliable and may corrupt your data. A good alternative would be https://www.npmjs.com/package/enmap , wich is atleast somewhat failsave and has easier useabilitty