Nobody can refer to a lexical variable outside its lexical scope by name.

However, if you hand a reference to that variable to another area, or even a reference to a closure that has visibility of the lexical variable, the variable can be tweaked at will.

Note that a subroutine has limited "call-by-reference" semantics as well, if you directly alter @_ rather than copy the values, as is routinely suggested.

And even if you had a copy of a top-level value, if that copy contains references, then the references are pointers into your original data structure. To fully insulate yourself, you must perform a deep copy.

-- Randal L. Schwartz, Perl hacker

In reply to Re: When is my variable not really mine? by merlyn
in thread When is my variable not really mine? by gaspodethewonderdog

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