Advanced Perl Programming

Advanced Perl ProgrammingSearch this book
Previous: B.8 Meta-InformationAppendix B
Syntax Summary
Next: B.10 Filehandles, Formats
 

B.9 Typeglobs

  1. Typeglobs assignment aliases identifiers. In the following example, all identifiers named a (scalar, array, hash, subroutine, filehandle, format) are also available as b:

    *a = *b ;     # Alias
    $b = 10;      # Same as modifying $a
    b();          # Same as calling a()
  2. Selective aliasing:

    *a = \$b ;    # Only $a aliased to $b
  3. Constants:

    *a = \10;     # Alias a typeglob to a reference to a constant
    $a = 20;      # Run-time error - "Attempt to modify read-only variable"


Previous: B.8 Meta-InformationAdvanced Perl ProgrammingNext: B.10 Filehandles, Formats
B.8 Meta-InformationBook IndexB.10 Filehandles, Formats

Library Navigation Links

Copyright © 2001 O'Reilly & Associates. All rights reserved.