$a = "foo bar";
$a = 0;
Dump $a;

# SV = PVIV(0x8155b10) at 0x8154654
#  REFCNT = 1
#  FLAGS = (IOK,pIOK)
#  IV = 0
#  PV = 0x816fa60 "foo bar"\0
#  CUR = 7
#  LEN = 8