I get:
Name "Our_package::my_variable" used only once: possible
typo at scope.pl line 41. for

print "4) \$Our_package::my_variable NOT DEFINED\n"
 if not (defined $Our_package::my_variable);

[download]
Shouldn't $Our_package::my_variable be something?
I'm looking for a typo but ...

You're right! I get the warning, too, but I let this happen on purpose. This generates a warning because I purposely refer to a variable declared 'my my_variable' in the other package. Since it's declared with 'my', it is (let's see if I get this right) lexically scoped only to the other package, so the calling program can't see it. As I understand it, a variable with lexical scoping means that it only exists within a particular textual area of code, in this case, the package "Our_package". I guess a solution to this would be for me to change the "#!/usr/bin/perl -w" to "#!/usr/bin/perl". Or maybe print a disclaimer about the warning. The point is, the user should learn from this that a 'my' variable in a package is not visible from outside that package.

In reply to Re: Re: Scoping Study Aid program by zeno
in thread Scoping Study Aid program by zeno

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.