how to reply discord js code example

Example 1: how to use msg.send instead of msg.reply discord.js javascript

//this is an event listener
client.on('message', message => {
  // If message is ping
  if (message.content === 'ping') {
    // Send pong back
    message.channel.send('pong');
  }
});

Example 2: discord.js reply to message author

message.reply("hello world");