I am learning to use the "map". Naturally I have been some question. For example:

my @numero = (1..100);
my %lista = map{$_,$_*2} @numero;
while (($num, $doble)= each(%lista)) { print "$num .... $doble\n";}

[download]

Here $ _ * 2 does not modify $ _ and the result is as expected:

33 .... 66
32 .... 64
90 .... 180
63 .... 126
21 .... 42
71 .... 142
7 .... 14 ...

Instead, working with regexp $ _ variable itself is modified:

my @palabras = qw ( arriba abajo contigo compaņero cariņo superfluo vi
+da);
my %cosa = map {$_, $_=~s/a/X/g} @palabras;
while (($uno, $dos)=each(%cosa)){print "$uno...$dos\n";}

[download]

And the result is not

arriba...XrribX
abajo...XbAjo ....
etc...

but

superfluo...
XbXjo...2
contigo...
compXņero...1

Where the %cosa key appears modified by ~ s and receives the number of substitutions made as value. It is also logical.

How do I use regexp and map if I want to have as a key each word in the array and assign it as value the result of a regexp operation on this key?

In reply to map and regexp. An newbie question by nando

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