Language Version: | ActionScript 3.0 |
Runtime Versions: | AIR 1.0, Flash Player 9, Flash Lite 4 |
Error
constructor function.
Typically, you throw a new Error object from within a try
code block that is caught by a catch
code block.
You can also create a subclass of the Error class and throw instances of that subclass.
More examples
Using try..catch..finally statements
Creating custom error classes
Responding to error events and status
Handling errors example: CustomErrors application
Learn more
Error handling in ActionScript 3.0
ActionScript 3.0 error-handling elements
Error-handling strategies
Comparing the Error classes
Core Error classes
Property | Defined By | ||
---|---|---|---|
constructor : Object
A reference to the class object or constructor function for a given object instance. | Object | ||
errorID : int [read-only]
Contains the reference number associated with the specific error message. | Error | ||
message : String
Contains the message associated with the Error object. | Error | ||
name : String
Contains the name of the Error object. | Error |
Method | Defined By | ||
---|---|---|---|
Creates a new Error object. | Error | ||
Returns the call stack for an error at the time of the error's
construction as a string. | Error | ||
Indicates whether an object has a specified property defined. | Object | ||
Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter. | Object | ||
Indicates whether the specified property exists and is enumerable. | Object | ||
Sets the availability of a dynamic property for loop operations. | Object | ||
Returns the string representation of this object, formatted according to locale-specific conventions. | Object | ||
[override]
Returns the string "Error" by default or the value contained in the Error.message property,
if defined. | Error | ||
Returns the primitive value of the specified object. | Object |
errorID | property |
errorID:int
[read-only] Language Version: | ActionScript 3.0 |
Runtime Versions: | AIR 1.0, Flash Player 9, Flash Lite 4 |
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
message | property |
public var message:String
Language Version: | ActionScript 3.0 |
Runtime Versions: | AIR 1.0, Flash Player 9, Flash Lite 4 |
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.
Related API Elements
name | property |
public var name:String
Language Version: | ActionScript 3.0 |
Runtime Versions: | AIR 1.0, Flash Player 9, Flash Lite 4 |
Contains the name of the Error object. By default, the value of this property is "Error
".
Related API Elements
Error | () | Constructor |
public function Error(message:String = "", id:int = 0)
Language Version: | ActionScript 3.0 |
Runtime Versions: | AIR 1.0, Flash Player 9, Flash Lite 4 |
Creates a new Error object. If message
is specified, its value is assigned
to the object's Error.message
property.
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.
|
Related API Elements
Example ( How to use this example )
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
getStackTrace | () | method |
public function getStackTrace():String
Language Version: | ActionScript 3.0 |
Runtime Versions: | AIR 1.0, Flash Player 9, Flash Lite 4 |
Returns the call stack for an error at the time of the error's construction as a string. 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: Error #1009: Cannot access a property or method of a null object reference at com.xyz::OrderEntry/retrieveData()[/src/com/xyz/OrderEntry.as:995] at com.xyz::OrderEntry/init()[/src/com/xyz/OrderEntry.as:200] at com.xyz::OrderEntry()[/src/com/xyz/OrderEntry.as:148]
The preceding listing shows the value of this method when called in a debugger version of Flash Player or code running in the AIR Debug Launcher (ADL). When code runs in a release version of Flash Player or AIR, the stack trace is provided without the file path and line number information, as in the following example:
TypeError: Error #1009: Cannot access a property or method of a null object reference at com.xyz::OrderEntry/retrieveData() at com.xyz::OrderEntry/init() at com.xyz::OrderEntry()
For Flash Player 11.4 and earlier and AIR 3.4 and earlier, stack traces
are only available when code is running in the debugger version of Flash
Player or the AIR Debug Launcher (ADL). In non-debugger versions of those runtimes, calling this
method returns null
.
String — A string representation of the call stack.
|
toString | () | method |
override public function toString():String
Language Version: | ActionScript 3.0 |
Runtime Versions: | AIR 1.0, Flash Player 9, Flash Lite 4 |
Returns the string "Error"
by default or the value contained in the Error.message
property,
if defined.
String — The error message.
|
Related API Elements
Example ( How to use this example )
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
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 theCustomError
class, which extendsError
. - 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); } }
Wed Nov 21 2018, 06:34 AM -08:00