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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.

Constructor

TypeError()
Creates a new TypeError object.

Instance properties

TypeError.prototype.message
Error message. Although ECMA-262 specifies that TypeError should provide its own message property, in SpiderMonkey, it inherits Error.prototype.message.
TypeError.prototype.name
Error name. Inherited from Error.
TypeError.prototype.fileName
Path to file that raised this error. Inherited from Error.
TypeError.prototype.lineNumber
Line number in file that raised this error. Inherited from Error.
TypeError.prototype.columnNumber
Column number in line that raised this error. Inherited from Error.
TypeError.prototype.stack
Stack trace. Inherited from 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.fileName)              // "Scratchpad/1"
  console.log(e.lineNumber)            // 2
  console.log(e.columnNumber)          // 2
  console.log(e.stack)                 // "@Scratchpad/2:2:3\n"
}

Creating a TypeError

try {
  throw new TypeError('Hello', "someFile.js", 10) 
} catch (e) {
  console.log(e instanceof TypeError)  // true
  console.log(e.message)               // "Hello"
  console.log(e.name)                  // "TypeError"
  console.log(e.fileName)              // "someFile.js"
  console.log(e.lineNumber)            // 10
  console.log(e.columnNumber)          // 0
  console.log(e.stack)                 // "@Scratchpad/2:2:9\n"
}

Specifications

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
TypeError 1 12 1 5.5 5 1
TypeError() constructor 1 12 1 5.5 5 1
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
TypeError 1 18 4 10.1 1 1.0
TypeError() constructor 1 18 4 10.1 1 1.0
Server
Node.js
TypeError 0.1.100
TypeError() constructor 0.1.100

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypeError