Re: Hash key intersection

my @A{ qw[ 1   3   5 6   ] } = ();
my @B{ qw[ 1 2 3 4   6 7 ] } = ();

print join'.', 
    ( exists $A{ $_ } ? 'A:' . $_ : '   ' ), 
    ( exists $B{ $_ } ? 'B:' . $_ : '   ' ) 
    for sort keys %{ { %A, %B } };

A:1.B:1
   .B:2
A:3.B:3
   .B:4
A:5.
A:6.B:6
   .B:7
[download]

Examine what is said, not who speaks.

"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail
Hooray!

Comment on Re: Hash key intersection Download Code

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•Re: Re: A man walks into a bar with a hash under each arm! by merlyn (Sage) on Dec 30, 2003 at 20:00 UTC
`sort keys %{ { %A, %B } }` [download] You'll get some spurious responses if %A and %B have values there, because you're mixing keys and values into a keys pile. Perhaps you wanted to add `keys` in front of each of the hashnames? -- Randal L. Schwartz, Perl hacker Be sure to read my standard disclaimer if this is a reply. update: OK, yeah, totally off base on this one. What was I thinking? {grin}	[reply] [d/l]
Re: •Re: Re: A man walks into a bar with a hash under each arm! by BrowserUk (Patriarch) on Dec 30, 2003 at 20:17 UTC
Actually, it's important that you don't use keys in front of the individual hashes, otherwise alternate keys get used as values in the construction of the anonymous hash. As I as showed, but with values added you get `@A{ qw[ 1 2 4 6 ] } = qw[ a b d f ]; @B{ qw[ 1 2 3 4 6 7 ] } = qw[ a b c d f g ]; print join '.', ( exists $A{ $_ } ? 'A:' . $_ : ' ' ), ( exists $B{ $_ } ? 'B:' . $_ : ' ' ) for sort keys %{ { %A, %B } }; A:1.B:1 A:2.B:2 .B:3 A:4.B:4 A:6.B:6 .B:7` [download] But using the extra key statements you get `print join'.', ( exists $A{ $_ } ? 'A:' . $_ : ' ' ), ( exists $B{ $_ } ? 'B:' . $_ : ' ' ) for sort keys %{ { keys %A, keys %B } }; A:1.B:1 A:6.B:6 .B:7` [download] Examine what is said, not who speaks. "Efficiency is intelligent laziness." -David Dunham "Think for yourself!" - Abigail Hooray!	[reply] [d/l] [select]