我有 TypeError: Cannot read property 'toString' of undefined答案

【问题标题】：I have the TypeError: Cannot read property 'toString' of undefined我有 TypeError: Cannot read property 'toString' of undefined
【发布时间】：2021-09-25 02:12:42
【问题描述】：

我正在制作一个不和谐的欢迎机器人，但存在一个问题，当有人加入服务器时它会发送此错误：

TypeError：无法读取未定义的属性“toString”

这里是源代码：

module.exports = (client) => {
    const channelid = "865471665168580628";
    client.on("guildMemberAdd", (member) => {
        const serverid = member.guild.id
        const guild = client.guilds.cache.get(serverid);

        console.log("member");
        const ruleschannel = guild.channels.cache.find(channel => channel.name === "rules");

        const message = `welcome <@${member.id}> to music and chill! please read the ${member.guild.channels.cache.get(ruleschannel).toString()} before you start chatting.`;

        const channel = member.guild.channels.cache.get(channelid);
        channel.send(message);
    })
}

有人可以帮帮我吗？

【问题讨论】：

可能这个是未定义的：member.guild.channels.cache.get(ruleschannel)

标签： javascript node.js discord discord.js typeerror

【解决方案1】：

这意味着member.guild.channels.cache.get(ruleschannel) 是undefined。由于ruleschannel是一个通道对象，而Collection#get()方法需要一个雪花，你需要使用它的id属性。

所以member.guild.channels.cache.get(ruleschannel.id) 应该可以工作。

更好的方法是检查ruleschannel 是否存在。此外，您只需在反引号内添加 rulesChannel 即可将其转换为频道链接。查看下面的代码：

client.on('guildMemberAdd', (member) => {
  // not sure why not just: const { guild } = member
  const guild = client.guilds.cache.get(member.guild.id);
  const rulesChannel = guild.channels.cache.find((channel) => channel.name === 'rules');

  if (!rulesChannel)
    return console.log(`Can't find a channel named "rules"`);

  const channel = guild.channels.cache.get(channelid);
  const message = `Welcome <@${member.id}> to music and chill! Please, read the ${rulesChannel}.`;

  channel.send(message);
});

【讨论】：