use CGI qw(:standard);
# later...
$cgi = new CGI();
map { ... } $cgi->param();
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There is no reason to do both. The :standard allows you to use most of the routines in CGI as standalone functions, but you're using the "OO" style calls, which don't require the function names to be imported to your code.

In other words, do either:

use CGI;
$cgi = CGI->new();        # my preference
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or:

use CGI qw(:standard);
map { ... } param();
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