Error Object and Error Types

The Error object is the base for all runtime errors. It can be thrown and caught with try...catch. There are several built‑in error types that extend Error, providing more specific error information.

Key Points

• Error: generic error.
• Built‑in error types: EvalError, RangeError, ReferenceError, SyntaxError, TypeError, URIError.
• Custom errors can be created by extending Error.

Code Example

try {
  throw new Error("Something went wrong");
} catch (err) {
  console.log(err.name); // "Error"
  console.log(err.message); // "Something went wrong"
  console.log(err.stack); // stack trace
}

// Specific error types
try {
  undefinedVariable; // ReferenceError
} catch (err) {
  console.log(err instanceof ReferenceError); // true
}

// Custom error
class ValidationError extends Error {
  constructor(message) {
    super(message);
    this.name = "ValidationError";
  }
}

try {
  throw new ValidationError("Invalid input");
} catch (err) {
  console.log(err.name); // "ValidationError"
  console.log(err.message); // "Invalid input"
}