Re: Find last position of an element in array

skipping past the sigil or brace mismatch, here is my five minute contribution...

perl -le '
  my @arr = (1,1,1,2,2,2,2,2,3,3,3,4,4,4,4,4,4,5,5,6);
  print (@arr - index((reverse(@arr)), 4));
'
__output__
17
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Comment on Re: Find last position of an element in array Download Code

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Re^2: Find last position of an element in array by kcott (Archbishop) on Mar 29, 2022 at 21:49 UTC
G'day dbuckhal, `17` = off-by-one error. Fix: use `$#arr` instead of `@arr`. `$ perl -le ' my @arr = (1,1,1,2,2,2,2,2,3,3,3,4,4,4,4,4,4,5,5,6); print ($#arr - index((reverse(@arr)), 4)); print "@arr[16, 17]"; ' 16 4 5` [download] — Ken	[reply] [d/l] [select]
Re^2: Find last position of an element in array by hippo (Archbishop) on Mar 30, 2022 at 09:49 UTC
You can avoid the maths with rindex: `$ perl -le ' my @arr = (1,1,1,2,2,2,2,2,3,3,3,4,4,4,4,4,4,5,5,6); print rindex( join (q{}, @arr), 4 ); ' 16` [download] 🦛	[reply] [d/l]