Using the Error Object

Using the Error Object

An Error object is usually passed to you in a catch statement (unless, for example, you throw the exception yourself and don't use an Error object). Table 3.18 lists the properties of this object.

Table 3.18. Properties of the Error Object

Property	NS2	NS3	NS4	NS6	IE3a	IE3b	IE4	IE5	IE5.5	IE6
description								x	x	x
		Contains a description of the error; as of IE5.5 and NS6, however, the message property is preferred.
fileName				x
		Holds the name of the file that caused the error.
lineNumber				x
		Holds the line number of the statement that caused the error.
message				x					x	x
		Contains a description of the error.
name				x					x	x
		Contains the name of the error that was thrown. The JavaScript error names are EvalError , RangeError , ReferenceError ,
		SyntaxError , TypeError , and URIError . General errors that you throw yourself are named Error .
number								x	x	x
		Internet Explorer only. Holds the Internet Explorer number for each error.

Using these properties, you have access to a great deal of information about the error that occurred.