state declares a lexically scoped variable, just like my.
However, those variables will never be reinitialized, contrary to
lexical variables that are reinitialized each time their enclosing block
is entered.
See Persistent Private Variables in perlsub for details.
If more than one variable is listed, the list must be placed in
parentheses. With a parenthesised list, undef can be used as a
dummy placeholder. However, since initialization of state variables in
list context is currently not possible this would serve no purpose.
state variables are enabled only when the use feature "state"
pragma
is in effect, unless the keyword is written as CORE::state
.
See also feature. Alternately, include a use v5.10
or later to the
current scope.