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Represents a runtime error.

Browser/User Agent Support

IE	Mozilla	Netscape	Opera	Safari
5.0+	1.0+	6.0+	7.0+	1.0+

Constructors

Constructor	IE	Mozilla	Netscape	Opera	Safari
Error Constructor Constructs a new instance of an Error object.	5.0+	1.0+	6.0+	7.0+	1.0+

Properties

Property	IE	Mozilla	Netscape	Opera	Safari
constructor Specifies the function that creates the Error prototype.	5.0+	1.0+	6.0+	7.0+	1.0+

description Description or message text of the error.	5.0+	no	no	no	no
description Description or message text of the error.
fileName Path or URL to the file that raised the error.	no	1.0+	6.0+	no	no
fileName Path or URL to the file that raised the error.
lineNumber Line number in file that raised the error.	no	1.0+	6.0+	no	no
lineNumber Line number in file that raised the error.
message Error message.	5.5+	1.0+	6.0+	7.0+	1.0+
message Error message.
name Error name.	5.5+	1.0+	6.0+	7.0+	1.0+
name Error name.
number Error number.	5.0+	no	no	no	no
number Error number.
prototype Reference to the Error object prototype.	5.0+	1.0+	6.0+	7.0+	1.0+
prototype Reference to the Error object prototype.
stack Stack trace that gives information about the context of the error.	5.0+	1.0+	6.0+	no	no

Methods

Method	IE	Mozilla	Netscape	Opera	Safari
toString Converts an Error object to a string.	5.0+	1.0+	6.0+	7.0+	1.0+
toString Converts an Error object to a string.

Throwing a generic error

Usually you create an Error object with the intention of raising it using the throw keyword. You can handle the error using the try...catch construct:

try {    throw new Error("Whoops!");} catch (e) {    alert(e.name + ": " + e.message);}

Handling a specific error

You can choose to handle only specific error types by testing the error type with the instanceof keyword:

try {    foo.bar();} catch (e) {    if (e instanceof EvalError) {        alert(e.name + ": " + e.message);    } else if (e instanceof RangeError) {        alert(e.name + ": " + e.message);    }    // ... etc}

You can also test the error'sname property to determine the error type. You can use this facility to create "user-defined" error types:

try {    var error = new Error("Whoops!");    error.name = "MyError";    throw error;} catch (e) {    if (e.name == "EvalError") {        alert(e.name + ": " + e.message);    } else if (e.name == "RangeError") {        alert(e.name + ": " + e.message);    }    // ... etc    else if (e.name == "MyError") {        alert(e.name + ": " + e.message);    }}

Remarks

Besides the baseError, there are six other core error types in JavaScript 1.5:

EvalError: raised when an error occurs executing code ineval()
RangeError: raised when a numeric variable or parameter is outside of its valid range
ReferenceError: raised when de-referencing an invalid reference
SyntaxError: raised when a syntax error occurs while parsing code ineval()
TypeError: raised when a variable or parameter is not a valid type
URIError: raised whenencodeURI() ordecodeURI() are passed invalid parameters

References

Availability

JavaScript 1.5 | JScript 5.5 | ECMAScript v3

Constructor Detail

Error Error([String message])

Constructs a new instance of an Error object.

String

message

Error message. (optional)

Property Detail

Object constructor - only

Specifies the function that creates the Error prototype.

Availability: JavaScript 1.5 | JScript 5.0 | ECMAScript v3

String description - only

Description or message text of the error.

Availability: JScript 5.0

String fileName - only

Path or URL to the file that raised the error.

Availability: JavaScript 1.5

Number lineNumber - only

Line number in file that raised the error.

Availability: JavaScript 1.5

String message

Error message.

Availability: JavaScript 1.5 | JScript 5.5 | ECMAScript v3

String name

Error name.

Availability: JavaScript 1.5 | JScript 5.5 | ECMAScript v3

Number number - only

Error number.

Availability: JScript 5.0

Object prototype - only

Reference to the Error object prototype.

Availability: JavaScript 1.5 | JScript 5.0 | ECMAScript v3

String stack - only

Stack trace that gives information about the context of the error.

Availability: JavaScript 1.5

Method Detail

toString() : String

Converts an Error object to a string.

Availability: JavaScript 1.5 | JScript 5.5 | ECMAScript v3

Oct	NOV	Dec
	04
2013	2014	2015