Your (and other's too) answer is correct and clear. But why no warnings are emitted in this case? like 'Redefine hash key not allowed at..' is similar to re-declare an already declared var, no?

For the OP question, the desired output can also be achievied reassigning the entire hash, like:
>perl -MData::Dumper -Mstrict -e 'sub t{ map {$_+=1 } @_}; my %h = (1 
+=> 2, 3 => 4); %h = t(%h); print Dumper \%h'
$VAR1 = {
          '4' => 5,
          '2' => 3
        };

[download]


L*
There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

In reply to Re^2: Modifying hash keys via aliasing by Discipulus
in thread Modifying hash keys via aliasing by vsespb

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