Throw [v1.1.04+]

Signals the occurrence of an error. This signal can be caught by a Try-Catch statement.

Throw , Expression



[v1.1.05+]: If omitted, an exception object is thrown with a default message.

Otherwise, specify a value to store in Catch's OutputVar.

Since this parameter is an expression, all of the following are valid examples:

throw 3
throw "literal string"
throw MyVar
throw i + 1
throw { what: "Custom error", file: A_LineFile, line: A_LineNumber } ; Throws an object

This parameter is always an expression, so variable references should not be enclosed in percent signs except to perform a double-deref.


Creates an object with properties, also common to exceptions created by runtime errors.

Exception(Message , What, Extra)

This object contains the following properties:

If What is omitted, it defaults to the name of the current function or subroutine. Otherwise, specify a string or a negative offset from the top of the call stack. For example, a value of -1 sets Exception.What to the current function or subroutine, and Exception.Line and Exception.File to the line and file which called it. However, if the script is compiled or the offset is invalid, What is simply converted to a string.

Message and Extra are converted to strings. These are displayed by an error dialog if the exception is thrown and not caught.

catch e
    MsgBox % "Error in " e.What ", which was called at line " e.Line 

SomeFunction() {
    throw Exception("Fail", -1)

Try, Catch, Finally, OnError()


See Try.