map confusion

knewter has asked for the wisdom of the Perl Monks concerning the following question:

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Re: map confusion by dragonchild (Archbishop) on Jan 19, 2005 at 19:39 UTC
map executes the command in {} on each of the elements in the the array and creates an array with the return values. So, if @links is an array of arrays, then @urls will be an array of the first elements in each of the sub-arrays in @links. Being right, does not endow the right to be rude; politeness costs nothing. Being unknowing, is not the same as being stupid. Expressing a contrary opinion, whether to the individual or the group, is more often a sign of deeper thought than of cantankerous belligerence. Do not mistake your goals as the only goals; your opinion as the only opinion; your confidence as correctness. Saying you know better is not the same as explaining you know better.	[reply]
Re: map confusion by mpeters (Chaplain) on Jan 19, 2005 at 19:40 UTC
It's basically the equivalent of this `my @urls; foreach (@links) { push(@urls, $_->[0]); }` [download] This means that since `@links` is an array of arrays, it will on ly use the first value in each of those arrays to place in `@urls`	[reply] [d/l] [select]
Re: map confusion by holli (Abbot) on Jan 19, 2005 at 19:43 UTC
say @links looks like this: `@links = ( [1,2,3], [4,5,6], [7,8,9] );` [download] and you apply `my @urls = map { $_->[0] } @links;` [download] @urls will end up as `@urls = (1,4,7);` [download] basically the code will produce a list that consists of the first elements of the anonymous arrays in @links. see perlref holli, regexed monk	[reply] [d/l] [select]
Re: map confusion by ccn (Vicar) on Jan 19, 2005 at 19:42 UTC
`@links` is AoA, (Array of Arrays) you can see it with: `use Data::Dumper; print Dumper(\@links);` [download] `map{$_->[0]}` returns a list which consist of first elements of each inner array	[reply] [d/l] [select]
Re: map confusion by gopalr (Priest) on Jan 20, 2005 at 05:01 UTC
Pls. refere for more info. about map	[reply]