Perl Quiz Series - Part I

Perl Questions:

Generic Questions:
1. What is 'our' used for ?
e.g our($VERSION, @ISA, @EXPORT, @EXPORT_OK, %EXPORT_TAGS)
2. What is 'exists' function used for?
3. What is 'uc' function used for ?
4. What is 'ref' function used for ?
5. What is 'defined' function used for ?
6. What is 'map' function used for ?
7. What is 'reverse' function used for ?
8. What is ' qq qw ' used for ?
9. What is 'tr' function used for ?
10. What is 'tie' function used for ?
11. What is ' push & pop ' function used for ?
12. What is ' undef ' function used for ?
13. What is ' bless ' function used for ?
14. What is ' self ' function used for ?
15. What is ' __FILE__ ' variable used for ?
16. What is ' __LINE__ ' variable used for ?
17. What is ' $_ ' used for ?
18. What is ' @_ ' used for ?
19. What is ' $$ ' used for ?
20. What is ' shift ' function used for ?
21. What is ' unless ' function used for ?
22. What is ' self ' function used for ?
23. What is ' untie ' function used for ?
24. What is 'split' function used for ?
25. What is 'splice' function used for ?
26. What is 'sort' function used for ?
27. What is 'keys' function used for ?
28. What is 'values' function used for ?
29. How to dereference a array reference $ref_a ? ( @$ref_a )
30. How to dereference a hash reference $ref_h ? ( %$ref_h )
31. How to dereference a scalar reference $ref_s ? ( $$ref_s )
32. What is difference between 'for & foreach' loop ?
33. What is 'while' function used for ?
34. What is 'last' function used for ?
35. What is 'exit' function used for ?
36. What is difference between 'die & warn' ?
37. What is 'eval' function used for ?
38. What is '$@' variable used for ?
39. What is 'Here document' ?
40. What is difference between 'exec & system' function?
41. How to set environment variable in perl ? ( $ENV{xx} )
42. What is ' $ ' (dollar pipe) used for ?
43. What is 'shebang'? ( #! ) --> first line of perl code
44. Can we use ' -w ' switch on first line OR 'use warnings' module alternatively ?
45. What is the difference between 'chomp & chop'?
46. How to invoke a unix shell command inside a perl script ? ( `ls -l` )
47. What is the difference between 'use & require' ?
48. What is '@ARGV' used for ? (Number of arguments)
49. What is ' . ' ( dot operator ) used for ?