How do you perform pattern matching and substitution using regular expressions in Perl?

In Perl, pattern matching and substitution using regular expressions are performed using the =~ operator and various built-in functions and operators. Here is an in-depth explanation of how pattern matching and substitution can be done using regular expressions in Perl: 1. Pattern Matching: * Pattern matching in Perl involves searching for a specific pattern within a string. * The =~ operator is used to match a regular expression against a string. If a match is found, it returns a true value. * Example: ``` perl`my $string = "Hello, World!"; if ($string =~ /Hello/) { print "Match found!"; }` ``` * Regular expression patterns can be as simple as literal characters or include metacharacters for more complex patterns. * Metacharacters like . (dot), (asterisk), + (plus), ? (question mark), and more provide powerful pattern-matching capabilities. 2. Capturing Matched Patterns: * Parentheses () are used to capture specific parts of a matched pattern for ....