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perl school; scalar/llst behavior in print

Posted on 2006-04-11
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Last Modified: 2010-03-05

%day = (
  Mon => "pudding" ,
  Tue => "soup",
  Wed => "carrots",
  Thr => "beans",
  Fri => "fish"
  );
 
What's the rule about list verse scalar context that
has the second print only printing the last value in a 'list'?

  print @day{'Mon', 'Tue'};         # print 'puddingsoup'

  print @day{'Mon', 'Tue'} . "\n"  # prints 'soup\n'
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Question by:hank1
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Expert Comment

by:ozo
ID: 16431584
the . operator works on scalars, so it puts its operands in scalar context.
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Author Comment

by:hank1
ID: 16431660
But why 'soup'?   Why not 'pudding'?
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Accepted Solution

by:
ozo earned 200 total points
ID: 16431707
perldoc perldata
       In a context not requiring a list value, the value of what appears to
       be a list literal is simply the value of the final element, as with the
       C comma operator.  For example,

           @foo = ('cc', '-E', $bar);

       assigns the entire list value to array @foo, but

           $foo = ('cc', '-E', $bar);

       assigns the value of variable $bar to the scalar variable $foo.  Note
       that the value of an actual array in scalar context is the length of
       the array; the following assigns the value 3 to $foo:

           @foo = ('cc', '-E', $bar);
           $foo = @foo;                # $foo gets 3
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