Error() constructor

message Optional

A human-readable description of the error.

options Optional

An object that has the following properties:

cause Optional

A property indicating the specific cause of the error. When catching and re-throwing an error with a more-specific or useful error message, this property can be used to pass the original error.

fileName Optional Non-standard

The value for the fileName property on the created Error object. Defaults to the name of the file containing the code that called the Error() constructor.

lineNumber Optional Non-standard

The value for the lineNumber property on the created Error object. Defaults to the line number containing the Error() constructor invocation.

When Error is used like a function, that is without new, it will return an Error object. Therefore, a mere call to Error will produce the same output that constructing an Error object via the new keyword would.

const x = Error("I was created using a function call!");

// above has the same functionality as following
const y = new Error('I was constructed via the "new" keyword!');

It is sometimes useful to catch an error and re-throw it with a new message. In this case you should pass the original error into the constructor for the new Error, as shown.

try {
  frameworkThatCanThrow();
} catch (err) {
  throw new Error("New error message", { cause: err });
}

For a more detailed example see Error > Differentiate between similar errors.

• A polyfill of Error with modern behavior like support cause is available in core-js
• throw
• try...catch
• Error causes (v8.dev/features)