无法读取 Discord.js 上未定义的属性“startsWith”

Question

I shall start this question with, i'm a beginner for discord.js, and please help me!

My whole index.js is:

const Discord = require('discord.js');
const client =  new Discord.Client();
const botsettings = require('./botsettings.json')

client.once('ready', () => {
    console.log("Ready!");
 });
client.on("message", async message =>{
    const playminecraftwithus = message.guild.channels.cache.find(channel => channel.name === 'play-minecraft-with-us')
    if(playminecraftwithus.content.startsWith("IGN:")) {
        return; 
 } else {
   message.delete();
}
});

client.login(botsettings.token);

and the problem is in this block:

client.on("message", async message =>{
    const playminecraftwithus = message.guild.channels.cache.find(channel => channel.name === 'play-minecraft-with-us')
    if(playminecraftwithus.content.startsWith("IGN:")) {
        return; 
 } else {
   message.delete();
}
});

but error message is like:

(node:13811) UnhandledPromiseRejectionWarning: TypeError: Cannot read property 'startsWith' of undefined | discord.js

If you need anything else, please tell me!

Answer 1

我想你的意思是输入message.content.startsWith()而不是playminecraftwithus.content.startsWith() 。

Answer 2

playminecraftwithus.content is undefined.

undefined has no method startsWith()

if you want to avoid an error, you could convert to string and use it.

Try this: (playminecraftwithus.content || "").startsWith()

|| means that when previous one is undefined use next. more details on here