尝试…catch 在 JavaScript (Discord.js) 中不起作用

Question

I'm working on a bot to fetch a user's avatar, I use try...catch for user mention detection, but it still throws an error.

And I tried a simple try...catch , and it throws an error SyntaxError: Identifier 'x' has already been declared :

try {
    let x = 1;
    let x = 2; // Variable already been declared
} catch (e) {
    console.log(e)
}

Here's my code:

// Get avatar by mention
try {
    client.users.fetch(msg.content.substr(prefix.length + 6, msg.content.length - prefix.length - 7)).then(result => {
        embeds.avatar
            .setTitle(`The avatar of ${msg.author.tag}`)
            .setImage(result.avatarURL({ dynamic: true }));
        msg.channel.send(embeds.avatar);
    });
} catch (e) {
    // Invalid user id
    logConsole('commandInvalidParam', msg);
    if (msg.content.length <= prefix.length + 14)
        embeds.commandInvalidParam.setDescription(`\`\`\`Invalid parameter at\n${msg.content}\n`);
    else
        embeds.commandInvalidParam.setDescription(`\`\`\`Invalid parameter at\n${msg.content.substr(0, prefix.length + 14)} ...\n`);
    for (let index = -4; index < prefix.length; index++)
        embeds.commandInvalidParam.setDescription(embeds.commandInvalidParam.description + ' ');
    embeds.commandInvalidParam.setDescription(embeds.commandInvalidParam.description + `^\`\`\`Type '${prefix}' for help`);
    msg.channel.send(embeds.commandInvalidParam);
}

IDE Using:

Virtual Studio Code

Version: 1.54.3 (user setup)

Commit: 2b9aebd5354a3629c3aba0a5f5df49f43d6689f8

Date: 2021-03-15T10:55:45.459Z

Electron: 11.3.0

Chrome: 87.0.4280.141

Node.js: 12.18.3

V8: 8.7.220.31-electron.0

OS: Windows_NT x64 10.0.18363

Answer 1

For the simple try...catch, you have already declared the x variable in your code. No 2 variables can be named the same thing, so it's going to give you a syntax error. If you want to change the value of x , just do x = 2 .

For your code, it can't find the user ID inside the fetch method. This could be because the prefix isn't the right length, or your substr method isn't getting the right parts of the method content. Either way, you should try declaring a variable with that substring, and then console.log ing the variable.

Answer 2

So, Here is an example of what a userinfo command should look like. I quickly made this with an index.js file with discord.js installed.

CODE:

module.exports = {
    name: 'userinfo',
    description: 'Get info on a user',
    execute(message, client) {
        const split = message.content.split(/ +/);
        const args = split.slice(1);

        const user = getUserFromMention(args[0], client);
        message.channel.send(`Name: ${user.username}, ID: ${user.id}, Avatar: ${user.displayAvatarURL({ dynamic: true })}`);
        // Other possible information
        // USER OBJECTS @ discord.js
        // ${user.id} ${user.username} ${user.discriminator}(AKA THE LAST 4 NUMBERS OF A DISCORD USERS ACCOUNT) ${user.bot?} ${user.system?} ${user.mfa_enabled}
        // ${user.locale?} ${user.verified?} ${user.email?} ${user.flags?} ${user.public_flags} ${user.premium}
        // src https://discord.com/developers/docs/resources/user#get-user
    }
};