Re^5: How to check if an array element reference exists or not

The point of using Data::Dumper is to get a textual representation of a data structure, so there is then no need to resort to screenshots of a debugger showing a scrolled window of a data structure.

Your debugger is misleading you. You are either not using strict, or you have two variables declared, @row and $row. They are different.

You seem to be wanting to check whether the 8th element in the array referenced by $row is defined, but you check whether the 8th element in the array @row is defined.

Again, use Data::Dumper to look at the data structure you're testing instead of relying on visual inspection combined with guesswork as to what data structure your code really is looking at.

if (defined $row->[7]) { ...
[download]

should work, according to my interpretation of the dump you show in the offsite link to a screenshot showing your debugger showing a data structure and some code.

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Re^6: How to check if an array element reference exists or not by corpx (Acolyte) on Apr 14, 2010 at 10:04 UTC
Thanks again for the reply. I'm not using strict as I'm just writing a function to complement code that somebody else has written. I ran the dumper on `$row`and it spit out a 3200KB text file. So instead, I ran the Dumper on `print Dumper ($row->[7]);` and got `$VAR1 = \undef;`. Running `if (defined ($row->[7]) )` when `$row->[7]` is `\undef;` returns true. I'm guessing that the reference is causing this?	[reply] [d/l] [select]
Re^7: How to check if an array element reference exists or not by Anonymous Monk on Apr 14, 2010 at 10:51 UTC
I'm guessing that the reference is causing this? What is this guessing? `$ perl -le"print \undef" SCALAR(0x3d5790) $ perl -le"print defined \undef" 1 $ perl -le"print \1" SCALAR(0x3d8284) $ perl -le"print defined \1" 1` [download]	[reply] [d/l]