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How can I access the index variable in map?

( #39590=categorized question: print w/ replies, xml ) Need Help??
Contributed by Anonymous Monk on Nov 02, 2000 at 07:02 UTC
Q&A  > arrays


Description:

# This works:
@a = (1,1,1); @b = (2,2,2); foreach $i (0 .. $#a) { $a[$i] += $b[$i]; }
but I'd like to use map. Is there a way to access the map index [$i] variable so I can do something like this:
@a = map $a[$i] + $_, @b;
Or is it simply not worth it?

Answer: How can I access the index variable in map?
contributed by Kanji

Try ...

@a = map { $a[$_] + $b[$_] } 0 .. $#b;

... or ...

my $i = 0; @a = map { $a[$i++] + $_ } @b;
Answer: How can I access the index variable in map?
contributed by chromatic

To my knowledge, there's no index iterator in the map construct, presumably because it operates on lists (not just arrays).

Stick with a for loop of some kind.

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