How to make the bot respond to a command they don't understand?

Question

Node.js

There is a VK bot written in node js that works on commands.

How to make if the bot was written a command that he does not know, he would answer something like "I don't understand you" or "Sorry, I don't know this command yet"

Answer 1

switch (command) {
    case 'one': return this.oneResult()
    case 'two': return this.twoResult()
    default: return 'Извините, пока я не знаю этой команды'
}

Answer 2

vk-io library