You can raise your exceptions to force an error condition even when the program code has not caused an exception.
Calling raise on its own raises an exception of the type RuntimeError or whatever exception is in the global variable $!:
raise # raises RuntimeError
By default, this will have no descriptive message associated with it. You can add a message as a parameter, like this:
raise "An unknown exception just occurred!"
You can raise a specific type of error:
You can create an object of a specific exception type and initialize it with a custom message:
raise ZeroDivisionError.new( "I'm afraid you divided by Zero" )
This is a simple example:
begin raise ZeroDivisionError.new( "divided by Zero" ) rescue Exception => e# from w w w .j a v a 2 s . c o m puts( e.class ) puts( "message: " + e.to_s ) end