my

See the current Perl documentation for my.

Here is our local, out-dated (pre-5.6) version:

my - declare and assign a local variable (lexical scoping)

my EXPR

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. See Private Variables via my() for details.