You don't even use the key in 
my %h_prefixed = map2 { ($_[0], "p".$_[1]) } %h;

[download]
You could do 
my %h_prefixed = %h;
$_ = "p$_" for values %h_prefixed;

[download]

In reply to Re: map2 {} grep2 {} ... by ikegami
in thread map2 {} grep2 {} ... by jozef

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