on message delete discord.js code example

Example 1: discord js delete message after time

message.reply('Invalid command')
  .then(msg => {
                msg.delete({ timeout: 20000 /*time unitl delete in milliseconds*/});
            })
  .catch(/*Your Error handling if the Message isn't returned, sent, etc.*/);

Example 2: discord.js messageDelete

client.on('messageDelete', (messageDelete) => {
    //Your code
});

//Note, you have to define client.
//Its best to run these events through something called a "event handler"

Example 3: how to send a message then delete it discord.js

message.reply('Invalid command')
  .then(msg => {
    msg.delete(10000)
  })