discord.js 无法读取未定义的属性“第一个”

Question

    name: 'purge',
    description: "Purge messages from the chat.",
    execute(message, args, Discord){
        const Error = new Discord.MessageEmbed()
        .setTitle("Correct Usage")
        .setColor('#4e5d94')
        .setDescription("```>purge [integer] [<channel>]```");
        if(message.member.permissions.has("MANAGE_MESSAGES")){
            if(!args[0]) return message.reply(Error);
            if(isNaN(args[0])) return message.reply(Error);
            if(args[0] > 150) return message.reply(Error.setDescription("```Integer should be smaller than 150```".setTitle("Error")));
            if(args[0] <= 0) return message.reply(Error.setDescription("```Integer should be bigger than 0```").setTitle("Error"));
            if(args[1]){
                try{
                    let channel = message.mentions.channel.first();
                    channel.bulkDelete(args[0]);
                    message.channel.send(Error.setTitle("Cleared").setDescription("```Successfully cleared " + args[0] + " messages from " + channel + "```"))
                }catch(e){
                    console.log(e)
                    message.reply(Error.setTitle("Error").setDescription("```Client has run into a problem , please contact the developers.```"))
                }
            } else{
                message.channel.bulkDelete(args[0]);
                message.channel.send(Error.setTitle("Cleared").setDescription("```Successfully cleared " + args[0] + " messages```"))
            }
        } else{
            message.reply(Error.setTitle("Permission").setDescription("```Insufficient permission.```"))
        }
    }
}

the error is : Cannot read property 'first' of undefined it used to work but for some reason it just wont no , can anyone help me? i have been trying to fix this thing for a bit now

Answer 1

You're looking for

let channel = message.mentions.channels.first();

(notice the plural channels )

https://discord.js.org/#/docs/main/stable/class/MessageMentions?scrollTo=channels

https://discord.js.org/#/docs/collection/master/class/Collection?scrollTo=first

Answer 2

It is a simple case of Typo my friend.

It should be

                    let channel = message.mentions.channels.first();

Since message.mentions.channels is the property which you are trying to access.