my $price = sprintf "£%d.%02d", $pounds||0, $pence||0;

##</code><code>##

my $price = sprintf "£%d.%02d", $pounds, $pence;

##</code><code>##

print 'a' + 'b', $/;    # warns
print []  + {},  $/;    # no warning

##</code><code>##

use v5.12;   # behaviour of split changed in 5.12.
sub a { split //, 'xyz'; 1 }  a();  # warns
sub b { split //, 'xyz' }  b(); 1;  # no warning

##</code><code>##

no warnings 'numeric';
no warnings 'once';
no warnings 'uninitialized';
no warnings 'void';