Don't say 
$courseindex = $courseindex + 1;

[download]

say rather 

$courseindex++;

[download]
if you need $courseindex for anything other than storing the array references in the right slot of @courselist.

You should then set $courseindex initially to 0 and increment it at the proper place, i.e. after having filled an array slot.

If you don't need to keep track of the index and just want to push a value (anonymous array) onto @courselist, do so: 

push @courselist, [$Institution, $CourseNumber, $Professor, $CourseTit
+le, $Enrollment];

[download]

--shmem 

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}

In reply to Re^2: How to fix error: Modification of a read-only value by shmem
in thread How to fix error: Modification of a read-only value by Gnat53

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