使用 discord.js 获取有关提到的用户/消息作者的信息

Question

**• Server Roles:** <@&${user._roles.join('> <@&')}> , ^^ Cannot read property 'join' of undefined I used message.member._roles.join('> <@&')}>`, But it always showed the roles of the user that wrote the command, and not the user that you mentioned.

Answer 1

Message.member is user who sent this message. If you want to get mentioned guild members you need to use message.mentions.members which returns an collection of mentioned users.
Your code should look like:

// To make sure that only one member is mentioned
if(message.mentions.members.size == 1){
    const roles = `<@&${message.mentions.members.first()._roles.join('> <@&')}>`
    message.channel.send(roles);
}

I recommend sending empty message first and then editing its content to add these mentions just to avoid pinging whole server.