javascript - How can I identify custom error

Question

I need to assigne an code/id to my custom error:

This is when I create the error:

var err=new Error('Numero massimo di cambi di username raggiunto');

Anyone to help me to understand how I can do this?

Answer 1

Define

function MyError(code, message) {
  this.code = code;
  this.message = message;
  Error.captureStackTrace(this, MyError);
}
util.inherits(MyError, Error);
MyError.prototype.name = 'MyError';

---

Raise

throw new MyError(777, 'Smth wrong');

---

Catch

if (err instanceof MyError) {
  console.log(err.code, err.message);
}