use strict and use warnings in perl

use strict and use warnings are two important pragmas (compiler directives) in Perl that help enforce stricter coding standards and catch potential errors during development. Here's an overview of each pragma:

1. use strict: The use strict pragma enforces the use of strict variable scoping rules in Perl, and requires that all variables be declared before use. It also prevents the use of symbolic references, and issues a compile-time error if any undefined variables are used in the code. For example:

use strict;
my $x = 42; # declare a variable with 'my'
print $x; # OK: $x is defined
print $y; # ERROR: $y is not defined

2. use warnings: The use warnings pragma enables additional warning messages during compilation and execution of Perl code. It can help catch potential errors or unintended behavior in the code. For example:

use warnings;
my $x = "42";
my $y = $x + 1; # WARNING: Argument "42" isn't numeric in addition (+) at test.pl line 3.
print $y; # prints 42

Together, use strict and use warnings can help improve the reliability and maintainability of Perl code by enforcing stricter coding standards and catching potential errors early in development. It's a good practice to include these pragmas at the beginning of every Perl script or module.