How Perl warnings are turn on and why is it important? | Perl Scripting Interiew Questions

In general, Perl excuse strange and also wrong code sometimes. Thus, the time spent for searching weird results and bugs in very high. You can identify common mistakes and strange places in the code easily when warnings are turned on. In the long run, the time required for debugging is saved a lot. There are numerous ways to turn on the warnings of Perl:
•    -w option is used on the command line for Perl one-liner
•    -w option on shebang line is used on windows or UNIX. Windows Perl interpreter do not require it.
•    For other systems, compiler documentation is checked or compiler warnings are selected.