You are viewing the version of this documentation from Perl 5.35.2. This is a development release of Perl.
my VARLIST
my TYPE VARLIST
my VARLIST : ATTRS
my TYPE VARLIST : ATTRS

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

Note that with a parenthesised list, undef can be used as a dummy placeholder, for example to skip assignment of initial values:

my ( undef, $min, $hour ) = localtime;

Redeclaring a variable in the same scope or statement will "shadow" the previous declaration, creating a new instance and preventing access to the previous one. This is usually undesired and, if warnings are enabled, will result in a warning in the shadow category.

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