In a nutshell, they catch many mistakes commonly made in Perl.

For more details, your local Perl install has the full scoop: 

% perldoc strict
% perldoc warnings

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Update: see also Some things that will make your life easier as a Perl coder

In reply to Re^3: MySQL Data Insertion Errors w/ Perl by trammell
in thread MySQL Data Insertion Errors w/ Perl by ingsoc747

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