Discord.js Getting data from a json file returns “undefined”

[AroTheBirb]

I’m trying to access data from a orders.json file it should list all “orders” however it says “undefined” when i try to do that as shown in the pic below

it also does the same thing when there aren’t any “orders” in the json file

the list command’s code:

const fsn = require("fs-nextra");
const Discord = require('discord.js');
module.exports = {
    name: 'list',
    description: 'List of all orders',
    aliases: ['allorders'],
    execute(message) {
        

        fsn.readJSON("./orders.json").then((orderDB) => {
            let orderString;
            for(let x in orderDB) {
                orderString = orderString + "`" + x + "`: " + orderDB[x].status + "\n";
                // add newline character at the end to display each "order" on a separate line
            }
            const exampleEmbed = new Discord.MessageEmbed()
                .setTitle('Here\'s a list of the current orders and their status.')
                .setDescription(orderString)
                .setTimestamp()
                .setFooter(message.member.user.tag, message.author.avatarURL());
            message.channel.send(exampleEmbed);
        });
    }
}

data in the json file are stored like this:

{
    "tip": {
        "orderID": "tip",
        "userID": "734532125021307001",
        "guildID": "745409671430668389",
        "guild": "Cybers Taco Stand Server",
        "channelID": "746423099871985755",
        "order": "a",
        "customer": "Aro#1221",
        "status": "Unclaimed",
        "ticketChannelMessageID": "not set"
    },
}

[RiversideRocks]

@AroTheBirb

orderDB[x].status

Should it be orderDB[x].tip.status?

[AroTheBirb]

no no no the orders.json file contains orders with random letters “tip” is one of the orders and i want the command to list them all from the json file

[WhiteNemo]

The problem is caused by not assigning any value to orderString when you declare it, and then proceed to use it as a string.
You can easily fix this by assigning orderString to an empty string at the moment of declaration; i.e. let orderString = ''.

The underlying reason for this is twofold:

1. An unassigned variable will return undefined when it is being evaluated.
2. When you concatenate a string with a non-string, the non-string is converted to a string.

Now, let us have a look at your for loop body:

orderString = orderString + '`' + x + '`: ' + orderDB[x].status + '\n'

At the first iteration of the for loop orderString is unassigned. As per point 1 the first iteration is therefore equal to:

orderString = undefined + '`' + x + '`: ' + orderDB[x].status + '\n'

Since undefined is a non-string, the first iteration of the loop can be further rewritten as per point 2:

orderString = 'undefined' + '`' + x + '`: ' + orderDB[x].status + '\n'

This is why undefined was prepended to the list in the first image.
For the second image, the same conversion is happening at .setDescription(orderString).