ReferenceError

The ReferenceError object represents an error when a variable that doesn't exist (or hasn't yet been initialized) in the current scope is referenced.

ReferenceError is a {{Glossary("serializable object")}}, so it can be cloned with {{DOMxRef("Window.structuredClone", "structuredClone()")}} or copied between Workers using {{domxref("Worker/postMessage()", "postMessage()")}}.

ReferenceError is a subclass of {{jsxref("Error")}}.

Constructor#

• {{jsxref("ReferenceError/ReferenceError", "ReferenceError()")}}
• : Creates a new ReferenceError object.

Instance properties#

Also inherits instance properties from its parent {{jsxref("Error")}}.

These properties are defined on ReferenceError.prototype and shared by all ReferenceError instances.

• {{jsxref("Object/constructor", "ReferenceError.prototype.constructor")}}
• : The constructor function that created the instance object. For ReferenceError instances, the initial value is the {{jsxref("ReferenceError/ReferenceError", "ReferenceError")}} constructor.
• {{jsxref("Error/name", "ReferenceError.prototype.name")}}
• : Represents the name for the type of error. For ReferenceError.prototype.name, the initial value is "ReferenceError".

Instance methods#

Inherits instance methods from its parent {{jsxref("Error")}}.

Examples#

Catching a ReferenceError#

try {
  let a = undefinedVariable;
} catch (e) {
  console.log(e instanceof ReferenceError); // true
  console.log(e.message); // "undefinedVariable is not defined"
  console.log(e.name); // "ReferenceError"
  console.log(e.stack); // Stack of the error
}

Creating a ReferenceError#

try {
  throw new ReferenceError("Hello");
} catch (e) {
  console.log(e instanceof ReferenceError); // true
  console.log(e.message); // "Hello"
  console.log(e.name); // "ReferenceError"
  console.log(e.stack); // Stack of the error
}

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("Error")}}