>perl -wE"say ''.!1"


>perl -wE"say 0+!1"
0

##</code><code>##

>perl -wE"say ''.0"
0

>perl -wE"say 0+0"
0

##</code><code>##

>perl -wE"say ''.''"


>perl -wE"say 0+''"
Argument "" isn't numeric in addition (+) at -e line 1.
0