• Pragmata
• Compiler directives that affect program compilation
• Beginners should consider the following mandatory!
• use strict
• Restricts unsafe constructs, requires declaration of variables, helps prevent common errors, feels more formal and less casual.
• use warnings / use diagnostics
• Provides helpful diagnostics. Older perl versions used a -w flag on the interpreter line.

        #!/usr/bin/perl

        use strict;
        use warnings;