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 serializable object, so it can be cloned with structuredClone() or copied between Workers using postMessage().

TypeError is a subclass of Error.

Constructor

• TypeError()
  • : Creates a new TypeError object.

Instance properties

Also inherits instance properties from its parent Error.

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

• TypeError.prototype.constructor
  • : The constructor function that created the instance object. For TypeError instances, the initial value is the TypeError constructor.
• 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 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

Browser compatibility

See also

• Error