1. What is Perl?
Perl is a high-level, general-purpose, interpreted programming language.
2. How do you declare a scalar variable in Perl?
Scalar variables in Perl are declared using the $ symbol.
3. What is the purpose of 'use strict;' in Perl?
'use strict;' helps catch errors and enforce good coding practices.
4. How do you create an array in Perl?
An array in Perl is created using the @ symbol.
5. What is the difference between 'my' and 'our' in Perl?
'my' declares a variable with a lexical scope, while 'our' declares a global variable.
6. How do you concatenate strings in Perl?
Strings in Perl can be concatenated using the '.' operator.
7. What is CPAN in Perl?
CPAN is the Comprehensive Perl Archive Network, a repository of Perl modules.
8. How do you write a comment in Perl?
Comments in Perl start with the # symbol.
9. What is a hash in Perl?
A hash is a collection of key-value pairs, declared using the % symbol.
10. How do you access an element in a Perl array?
Array elements are accessed using their index in square brackets.
11. What is the purpose of 'chomp' in Perl?
'chomp' removes the newline character from the end of a string.
12. How do you open a file in Perl?
Files in Perl are opened using the 'open' function.
13. What is the difference between 'eq' and '==' in Perl?
'eq' is used for string comparison, while '==' is used for numeric comparison.
14. How do you define a subroutine in Perl?
Subroutines in Perl are defined using the 'sub' keyword.
15. What is the default variable in Perl?
The default variable in Perl is $_.
16. Explain the concept of context in Perl.
Context in Perl determines how an expression is evaluated, either in scalar or list context.
17. What is the difference between 'require' and 'use' in Perl?
'require' is used at runtime, while 'use' is evaluated at compile time.
18. How do you handle exceptions in Perl?
Exceptions in Perl are handled using 'eval' blocks.
19. What is the purpose of the 'bless' function in Perl?
'bless' associates an object with a class in Perl.
20. How do you create a package in Perl?
Packages in Perl are created using the 'package' keyword.
21. Describe the use of regular expressions in Perl.
Regular expressions in Perl are used for pattern matching and text manipulation.
22. How do you pass arguments to a subroutine in Perl?
Arguments are passed to a subroutine via the special array @_.
23. What is the difference between 'die' and 'warn' in Perl?
'die' terminates the program, while 'warn' issues a warning and continues execution.
24. How do you use references in Perl?
References in Perl are created using the backslash operator and dereferenced using the appropriate symbol.
25. What is the purpose of the 'AUTOLOAD' subroutine in Perl?
'AUTOLOAD' is used to handle undefined subroutine calls dynamically.
26. How do you implement object-oriented programming in Perl?
Object-oriented programming in Perl is implemented using packages, 'bless', and method calls.
27. What is the difference between 'local' and 'my' in Perl?
'local' temporarily backs up and replaces global variables, while 'my' creates lexically scoped variables.
28. How do you work with filehandles in Perl?
Filehandles in Perl are used to read from or write to files and are created using the 'open' function.
29. What is the purpose of the 'tie' function in Perl?
'tie' binds a variable to a package class to override its behavior.
30. How do you use modules in Perl?
Modules in Perl are included using the 'use' or 'require' statements.
31. What are Perl closures, and how are they used?
Closures in Perl are subroutines that capture and use variables from their surrounding scope.
32. Explain the concept of Perl's garbage collection.
Perl uses reference counting for garbage collection to manage memory.
33. How do you implement polymorphism in Perl?
Polymorphism in Perl is achieved through method overriding in object-oriented programming.
34. What is the purpose of the 'DESTROY' method in Perl?
The 'DESTROY' method is called automatically when an object goes out of scope.
35. How do you create anonymous subroutines in Perl?
Anonymous subroutines in Perl are created using the 'sub' keyword without a name.
36. What is the difference between 'can' and 'isa' methods in Perl?
'can' checks if an object can perform a method, while 'isa' checks if it belongs to a class.
37. How do you handle circular references in Perl?
Circular references in Perl can be handled using the 'weaken' function from Scalar::Util.
38. What is the purpose of the 'eval' function in Perl?
The 'eval' function in Perl is used to catch runtime errors or execute code dynamically.
39. How do you use the 'overload' pragma in Perl?
The 'overload' pragma in Perl is used to define custom behavior for operators in objects.
40. What are Perl typeglobs, and how are they used?
Typeglobs in Perl are used to create aliases for variables or filehandles.
41. Explain the use of the 'SUPER' keyword in Perl.
The 'SUPER' keyword in Perl is used to call a method from a parent class.
42. How do you implement inheritance in Perl?
Inheritance in Perl is implemented by setting the @ISA array in a package.
43. What is the purpose of the 'UNIVERSAL' package in Perl?
The 'UNIVERSAL' package provides default methods for all Perl classes.
44. How do you work with threads in Perl?
Threads in Perl are created and managed using the 'threads' module.
45. What is the difference between deep copy and shallow copy in Perl?
A shallow copy duplicates references, while a deep copy duplicates the entire data structure.
46. How do you use the 'DBI' module for database interaction in Perl?
The 'DBI' module in Perl is used to connect to and interact with databases.
47. What is the purpose of the 'lock' function in Perl?
The 'lock' function in Perl is used to manage shared variables in threaded programs.
48. How do you profile Perl code for performance optimization?
Perl code can be profiled using the 'Devel::NYTProf' module.
49. What is the significance of the 'BEGIN' and 'END' blocks in Perl?
'BEGIN' runs code during compilation, and 'END' runs code at program termination.
50. How do you use the 'Moose' framework for object-oriented programming in Perl?
The 'Moose' framework simplifies object-oriented programming by providing modern features.