Re^3: Loop once on condition 1, many times on cond. 2?

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Re^4: Loop once on condition 1, many times on cond. 2? by punch_card_don (Curate) on Oct 09, 2008 at 15:37 UTC
Excellent, thanks. I'll read up on this notation. Time flies like an arrow. Fruit flies like a banana.	[reply]
Re^5: Loop once on condition 1, many times on cond. 2? by AnomalousMonk (Archbishop) on Oct 09, 2008 at 18:19 UTC
Some maintainability may be gained at the cost of some concision by separating out loop list generation: `my @keys_to_process = $x eq 'key_1' ? keys %my_hash : exists $my_hash{$x} ? ($x) : () # default - nothing to do ; foreach $key (@keys_to_process) { do_something_with($key); }` [download] Further, because the above will loop over all keys if `$x eq 'key_1'` is true even if `'key_1'` does not exist in the hash (which may or may not be what you want: Your Logic May Vary), perhaps re-order list generation: `my @keys_to_process = ! exists $my_hash{$x} ? () : $x eq 'key_1' ? keys %my_hash : ($x) ;` [download]	[reply] [d/l] [select]
Re^5: Loop once on condition 1, many times on cond. 2? by gone2015 (Deacon) on Oct 09, 2008 at 16:57 UTC
You can chain these suckers... so to ensure you do nothing if `$x` doesn't appear in `%my_hash`: `foreach $key ( ($x eq 'key_1') ? keys %my_hash : exists $my_hash($x) +? $x : () ) { do a bunch of stuff }` [download] noting that if `$x` does not exist, what you want is an empty list.	[reply] [d/l] [select]