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.

Properties

TypeError.prototype

Allows the addition of properties to a TypeError object.

Methods

The global TypeError contains no methods of its own. However, it does inherit some methods through the prototype chain.

TypeError instances

Properties

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 compatibility

See also

• Error