TypeError

The TypeError object represents an error when an operation could not be performed, typically (but not exclusively) when a value is not of the expected type.

A TypeError may be thrown when:

• an operand or argument passed to a function is incompatible with the type expected by that operator or function; or
• when attempting to modify a value that cannot be changed; or
• when attempting to use a value in an inappropriate way.

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

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

Constructor#

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

Instance properties#

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

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

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

Instance methods#

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

Examples#

Catching a TypeError#

try {
  null.f();
} catch (e) {
  console.log(e instanceof TypeError); // true
  console.log(e.message); // "null has no properties"
  console.log(e.name); // "TypeError"
  console.log(e.stack); // Stack of the error
}

Creating a TypeError#

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

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("Error")}}