Language Version: | ActionScript 3.0 |
The Error class contains information about an error that occurred in a script. In developing ActionScript 3.0 applications,
when you run your compiled code in the debugger version of Flash Player, a dialog box displays exceptions of type Error,
or of a subclass, to help you troubleshoot the code.
You create an Error object by using the
Error
constructor function.
Typically, you throw a new Error object from within a
try
code block that is caught by a
catch
or
finally
code block.
You can also create a subclass of the Error class and throw instances of that subclass.
View the examples
errorID:int
[read-only]
Language Version: | ActionScript 3.0 |
Contains the reference number associated with the specific error message. For a custom Error object,
this number is the value from the
id
parameter supplied in the constructor.
Implementation public function get errorID():int
public var message:String
Language Version: | ActionScript 3.0 |
Contains the message associated with the Error object. By default, the value of this property
is "
Error
". You can specify a
message
property when you create an
Error object by passing the error string to the
Error
constructor function.
See also
public var name:String
Language Version: | ActionScript 3.0 |
Contains the name of the Error object. By default, the value of this property is "
Error
".
See also
public function Error(message:String = "", id:int = 0)
Language Version: | ActionScript 3.0 |
Creates a new Error object. If
message
is specified, its value is assigned
to the object's
Error.message
property.
Parameters | message:String (default = " ") — A string associated with the Error object; this parameter
is optional. |
|
| id:int (default = 0 ) — A reference number to associate with the specific error message. |
See also
Example
The following example creates a new Error object
err
and then, using the
Error()
constructor, assigns the string
"New Error Message"
to
err
.
var err:Error = new Error();
trace(err.toString()); // Error
err = new Error("New Error Message");
trace(err.toString()); // Error: New Error Message
public function getStackTrace():String
Language Version: | ActionScript 3.0 |
Returns the call stack for an error as a string at the time of the error's construction (for the debugger version
of Flash Player only). As shown in the following example, the first line of the return value is the
string representation of the exception object, followed by the stack trace elements:
TypeError: null cannot be converted to an object
at com.xyz.OrderEntry.retrieveData(OrderEntry.as:995)
at com.xyz.OrderEntry.init(OrderEntry.as:200)
at com.xyz.OrderEntry.$construct(OrderEntry.as:148)
Returns | String — A string representation of the call stack. |
override public function toString():String
Language Version: | ActionScript 3.0 |
Returns the string
"Error"
by default or the value contained in
Error.message
property,
if defined.
ReturnsSee also
Example
The following example creates a new Error object
err
and then, using the
Error()
constructor, assigns the string
"New Error Message"
to
err
. Finally, the
message
property is set to
"Another New Error Message"
,
which overwrites
"New Error Message"
.
var err:Error = new Error();
trace(err.toString()); // Error
err = new Error("New Error Message");
trace(err.toString()); // Error: New Error Message
err.message = "Another New Error Message";
trace(err.toString()); // Error: Another New Error Message
The following example uses the
ErrorExample
class to show
how a custom error can be generated. This is accomplished with the following
steps:
-
A local variable
nullArray
of Array type is declared, but notice
that a new Array object is never created.
-
The constructor attempts to load a value into the uninitialized array by using
the
push()
method within an error handling code segment that catches a
custom error by using the
CustomError
class, which extends
Error
.
-
When the CustomError is thrown, the constructor catches it and then outputs an
error message by using the
trace()
statement.
package
{
import flash.display.Sprite;
public class ErrorExample extends Sprite
{
private var nullArray:Array;
public function ErrorExample()
{
try
{
nullArray.push("item");
}
catch(e:Error)
{
throw new CustomError("nullArray is null");
}
}
}
}
class CustomError extends Error
{
public function CustomError(message:String)
{
super(message);
}
}
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Sun Oct 19 2008, 07:03 PM -07:00