如何修复“无法读取未定义的属性'长度'”和 Args 输入在我的扫雷命令中不起作用 - Discord.js

Question

I am making a Minesweeper command using discord.js. It is using args to collect the user's inputs for the Minesweeper board. (ie a3, a3f [f for flag]). However, the command runs perfect, it shows the board with letter and numbers on the top and side. The main issue I am having is the command will not take those response arg inputs that I put in. This is how the user will be able to play.

After the round ends (without any input) It throws the error Cannot read property 'length' of undefined . This is somewhat referred to these lines of code.

const filter = msgs => {
    const param = msgs.content.toLowerCase().split(" ");
    return param.length === 2 && alphabet.includes(param[0]) && parseInt(param[1], 10) < 7 && !answered.includes(param.join("")) && msgs.author.id === msg.author.id;
};

param[0] = alphabet.includes[param[0]];
param[1] = parseInt(param[1], 10) - 1;
if (board[param[1]][param[0]] === "💣") {
    for (let i = 0; i < board.length; i++) {
        for (let j = 0; j < board[i].length; i++) {
            if (board[i][j] === "💣") showboard[i][j] = "💣";
        }
    }

I believe this is what is causing the issue of my minesweeper command. I am not 100% certain but I think I might be able to fix it by defining the params to args[0]

I have the full code here for the command: https://natebot-haste.glitch.me/lusarovisa.js

I am honestly not too sure what to do from this point, I've attempted changing the param definition and since code seems perfect, I might as well ask here.

Answer 1

Since it seems to be a problem with Params being either null or undefined how about doing a check like this?

 const filter = msgs => {
        const param = msgs.content.toLowerCase().split("");
        if(param && param.length === 2) {
            return alphabet.includes(param[0]) && parseInt(param[1], 10) < 7 && !answered.includes(param.join("")) && msgs.author.id === msg.author.id;
        }
        else {
            return false
        }
      };
};