in reply to Re^2: return value of chomp is false?
in thread return value of chomp is false?

Not it doesn't. I suspect you used a comma instead of a semi-colon.

By the way, there's also

use List::MoreUtils qw( apply ); my $names = join '|', apply { chomp } <STDIN>;
and
use Nested::Loops qw( Filter ); my $names = join '|', Filter { chomp } <STDIN>;