For unrelated reasons*, I don't like working at the global level. This has the side-effect of avoiding the issue. 

#!/usr/bin/perl -w

{
   my ( $length, $breadth, $height ) = ( 10, 20, 30 );
   my $volume = calc_volume( $length, $breadth, $height );
   print "\nvolume = $volume\n";
}

sub calc_volume {
    my ( $length, $breadth, $height ) = @_;
    my $volume = $length * $breadth * $height;
    return $volume;
}

[download]

While the snippet you provided has two variables with the same name in scope at the same time, the snippet I provided does not.

* — First, it makes the scope of variables much larger than it needs to be. Secondly, global objects are destroyed in an unpredictable order. That means a child object can be reaped before its owners is, which is bad if you have a custom destructor.

In reply to Re: Confusion in naming variables in subroutines by ikegami
in thread Confusion in naming variables in subroutines by Anonymous Monk

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