class AppError extends Error {
  constructor(message, code) {
    super(message);
    this.name = "AppError";
    this.code = code;
  }
}

function riskyOperation(value) {
  if (value === null) throw new AppError("Null value", 404);
  if (typeof value !== "number") throw new TypeError("Not a number");
  if (value < 0) throw new RangeError("Negative value");
  return value * 2;
}

const inputs = [42, null, "hello", -5];
const results = inputs.map((input) => {
  try {
    return riskyOperation(input);
  } catch (err) {
    if (err instanceof AppError) return `AppError:${err.code}`;
    if (err instanceof TypeError) return `TypeError`;
    if (err instanceof RangeError) return `RangeError`;
    return `UnknownError`;
  }
});

console.log(results);