my

my EXPR
my TYPE EXPR
my EXPR : ATTRS
my TYPE EXPR : ATTRS

A my declares the listed variables to be local (lexically) to the enclosing block, file, or eval. If more than one value is listed, the list must be placed in parentheses.

The exact semantics and interface of TYPE and ATTRS are still evolving. TYPE is currently bound to the use of fields pragma, and attributes are handled using the attributes pragma, or starting from Perl 5.8.0 also via the Attribute::Handlers module. See perlsub/"Private Variables via my()" for details, and fields, attributes, and Attribute::Handlers.