Check syntax question...

[Bob]

I am going through another persons code. I turned on "strict" and
"warnings" and I am not sure what to do about this warning:

"Scalar value @_[0] better written as $_[0] at update_patch.pl line
939."

Should I change it to reflect what is suggested? Why did it suggest
that? I am just a wee learner of Perl.

Robert

 

[Paul Lalli]

I am going through another persons code. I turned on "strict" and
"warnings" and I am not sure what to do about this warning:

"Scalar value @_[0] better written as $_[0] at update_patch.pl line
939."

Should I change it to reflect what is suggested?

Almost certainly yes. We'd have to see the code to be 100% certain, but
the chances of it not being better changed are very unlikely.

Why did it suggest that?

In Perl, $ is used to mean scalar, which is a single value. @ is used to
mean array, a collection of values. The syntax of @array[2,3,4] for
example, means "the set containing the third, fourth, and fifth elements
of @array". The syntax @array[2] means "the set containing the third
element of @array". $array[2], on the other hand, means simply "the third
element of @array". There is almost never a reason to use a collection
containing one element where all you actually need is that one element.
That is what that warning is about.

I am just a wee learner of Perl.

Read up! Take a look at
perldoc perlsyn
for the syntax of Perl, and
perldoc perldiag
for a description and explanation of all the warnings you may encounter.


Paul Lali

 

[Tad McClellan]

I am going through another persons code. I turned on "strict" and
"warnings" and I am not sure what to do about this warning:

"Scalar value @_[0] better written as $_[0] at update_patch.pl line
939."

Should I change it to reflect what is suggested?

Yes.


Why did it suggest
that?

Because sometimes it makes a difference.

I am just a wee learner of Perl.

Your Question is Asked Frequently:

What is the difference between $array[1] and @array[1]?