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.
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
Specification |
---|
ECMAScript Language Specification # sec-native-error-types-used-in-this-standard-typeerror |
Browser compatibility
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