use Devel::Peek;

$var = "3";
Dump $var;
print "^^^^^^^^^^\n";

$x = $var + 0;
Dump $var;
print "^^^^^^^^^^\n";

$var += 0;
Dump $var;
print "^^^^^^^^^^\n";

##</code><code>##

SV = PV(0x4fae04) at 0x612d94
  REFCNT = 1
  FLAGS = (POK,pPOK)
  PV = 0x5ffdcc "3"\0
  CUR = 1
  LEN = 12
^^^^^^^^^^
SV = PVIV(0x610f84) at 0x612d94
  REFCNT = 1
  FLAGS = (IOK,POK,pIOK,pPOK)
  IV = 3
  PV = 0x5ffdcc "3"\0
  CUR = 1
  LEN = 12
^^^^^^^^^^
SV = PVIV(0x610f84) at 0x612d94
  REFCNT = 1
  FLAGS = (IOK,pIOK)
  IV = 3
  PV = 0x5ffdcc "3"\0
  CUR = 1
  LEN = 12
^^^^^^^^^^