DB<116> use warnings;0+"2"
 => 2

  DB<117> 0+"ss2"
 => 0

  DB<118> 0+"3ss2"
 => 3

  DB<119> use warnings;0+"3ss2"
Argument "3ss2" isn't numeric in addition 

##</code><code>##

>>> a="ss2";  0+parseInt(a)
NaN
>>> a="3ss2";  0+parseInt(a)
3

##</code><code>##

>>> a="2";  0+a
"02"
>>> a="2";  0+a-0
2