Discord.js client.on

Question

My code is this, do I also have to have the client.on('message', message => { or not?

client.on('message', message => {
  if (message.content.startsWith(prefix + "ping")) {
    message.channel.send('Pong! <:Pingsock:433019097005948938>');
  }
});

client.on('message', message => {
  if (message.content.startsWith(prefix + "avatar")) {
    message.reply(message.author.avatarURL);
  }
});

Solution

If your question is if you should have one event per command, absolutely not.
There is a limit for how many events a bot can "subscribe", and you would use all of them with just a few commands. And also that would be terrible for performance because it will trigger all the events for every single message sent.
You should instead have one event and check which command was used.

client.on("message", message => {
    if(message.content.startsWith(prefix + "ping")){
        message.channel.send('Pong! <:Pingsock:433019097005948938>');

    } else if (message.content.startsWith(prefix + "avatar")) {
        message.reply(message.author.avatarURL);

    }
}

Comments

[Oliver]

The message event will be triggered when the client gets a new incoming message. Having multiple listeners for one event is, as André said, useless, and will consume more ram than necessary.