#! perl
use strict;
use warnings;

for (
        0,
        0E0,
       '0E0',
        0.0,
       '0.0',
        0.00,
       '0.00',
        00,
       '00',
       '0',
       '0 but true',
       '0 BUT TRUE',
       '0 but true ',
       '1 and true',
    )
{
    printf "%-11s  %d  %s\n", $_, ($_ + 0), ($_ ? 'true' : 'false');
}