my $a = 123; 
{ 
    my $a; 
    print $a; ## produces "Use of uninitialized value $a in print ... " because the above new $a is entirely new; thus uninitialised.
}

print $a;; ## prints: 123

##</code><code>##

our $a = 123; 
{ 
    our $a; ## produces ""our" variable $a redeclared at ..." references the same variable as the first our $a
    print $a; ## prints 123 ## New scope, same variable, existing value.
} 
print $a;; ##  prints 123