DOMException
For languages and runtime platforms that support them, structured exceptions provide a way to separate the code that deals with abnormal or unexpected problems from the normal flow of execution. For languages that don't support exceptions, such as ECMAScript or Perl, these conditions are reported to your program as error codes from the method that recognized the condition.
The ExceptionCode is an
integer value that indicates what type of exception was detected.
The following ExceptionCodes
are defined, with unused numeric codes reserved for future use by
the W3C.