This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.1)


is the list of rules that gives named message groups used in functions like On and Quiet.
  • Named groups can also appear on the right-hand side of the definitions.
  • $MessageGroups can be reset. Any string can be used as the name of a message group.
  • Predefined named message groups include:
"Compiler"warnings associated with compiled code
"Graphics"warnings associated with graphics generation
"Obsolete"warnings for obsolete functions and packages
"Packing"notifications associated with packed arrays
"Spelling"spell-checking messages for symbol names
"Symbolics"warnings associated with symbolic computation
Get the list of the existing message groups:
Get the list of the existing message groups:
Click for copyable input
Get the list of messages associated with packed arrays:
Define a new group comprised of the existing groups:
Check for unpacking of arrays:
This produces rational numbers and has to unpack:
Using inexact numbers leaves the array packed:
Quiet the compiler warnings that allow the evaluation to proceed:
New in 7