Microsoft® JScript®
number Property
 Language Reference 
Version 5 

See Also                     Applies to

Returns or sets the numeric value associated with a specific error. The Error object's default property is number.
object.number [= errornumber]

The number property syntax has these parts:

Part Description
object Any instance of the Error object.
errornumber An integer representing an error.

An error number is a 32-bit value. The upper 16-bit word is the facility code, while the lower word is the actual error code.

The following example illustrates the use of the number property:

try {
  x = y         		             // Cause an error.
catch(var e) {                         // Create local variable e.
  document.write(e)                    // Prints "[object Error]".
  document.write(e.number>>16 & 0x1FFF)// Prints 10, the facility code.
  document.write(e.number & 0xFFFF)    // Prints 5009, the error code.
  document.write(e.description)        // Prints "'y' is undefined".