Re: Concerning hash operations (appending, concatenating)

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Re^2: Concerning hash operations (appending, concatenating) by thor (Priest) on Mar 24, 2005 at 16:57 UTC
This is actually really, really useful. People often ask the question "how do I store a value in a hash only if it's a new value?". Here's the answer. thor `Feel the white light, the light within Be your own disciple, fan the sparks of will For all of us waiting, your kingdom will come`	[reply]
Re^3: Concerning hash operations (appending, concatenating) by japhy (Canon) on Mar 24, 2005 at 17:50 UTC
Yeah, but I don't like it. I don't like assigning X to itself like the example does. I'd prefer a slightly long-winded approach: `$hash{$_} = $otherhash{$_} for grep !exists $hash{$_}, keys %otherhash +;` [download] Or: `{ my @new_keys = grep !exists $hash{$_}, keys %otherhash; @hash{@new_keys} = @otherhash{@new_keys}; }` [download] _____________________________________________________ Jeff `japhy` Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and `perl` hacker How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart	[reply] [d/l] [select]
Re^4: Concerning hash operations (appending, concatenating) by RazorbladeBidet (Friar) on Mar 24, 2005 at 17:53 UTC
But isn't that creating arrays and going through loops that are unnecessary? -------------- "But what of all those sweet words you spoke in private?" "Oh that's just what we call pillow talk, baby, that's all."	[reply]
Re^5: Concerning hash operations (appending, concatenating) by japhy (Canon) on Mar 24, 2005 at 18:24 UTC
Re^6: Concerning hash operations (appending, concatenating) by Tanktalus (Canon) on Mar 24, 2005 at 18:45 UTC
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Re^2: Concerning hash operations (appending, concatenating) by RazorbladeBidet (Friar) on Mar 24, 2005 at 17:55 UTC
Thanks for that one Zaxo (among others), I hadn't thought of these ; but is there any way to eliminate the redundancy of flattening the hash in `%hash = (%hash, e => 'f', g => 'h', i => 'j');` [download] ?? -------------- "But what of all those sweet words you spoke in private?" "Oh that's just what we call pillow talk, baby, that's all."	[reply] [d/l]
Re^2: Concerning hash operations (appending, concatenating) by ABCXYZ (Novice) on Dec 25, 2012 at 23:06 UTC
<This is one idiom, `<%hash = (%hash, e => 'f', g => 'h', i => 'j'); <%hash = (%otherhash, %hash);` [download] This code reminds me of writing the comma operator in this way: "`,=`", so to concatenate a hash: `my %hash1 =qw/ One 1 Two 2 Three 3/; my %hash2 =qw/ Four 4 Five 5 Six 6/; %hash1 ,= %hash2; say keys %hash1;` [download] And I've checked it, it works in Perl6, the future version of Perl.	[reply] [d/l] [select]


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