Question

Code as follows:

use strict;
use warnings;

Is use warnings; necessary here?

Answer 1

Yes, it’s necessary.

use strict and use warnings do different things.

From the strict module’s manpage:

strict − Perl pragma to restrict unsafe constructs

From perlrun (for -w):

prints warnings about dubious
constructs, such as variable names
that are mentioned only once and scalar variables that are
used
before being set, redefined subroutines, references to
undefined
filehandles or filehandles opened read-only that you are
attempting to write on, values used as a number that don’t
look
like numbers, using an array as though it were a scalar, if
your
subroutines recurse more than 100 deep, and innumerable other
things.