well, In the program below, i am not getting the result prem even though I would expect it.. I justify my expectations after the program: 
use Data::Dumper;
use strict;
use warnings;

sub risk_eval {

    {
    'age_22' => 2,
          'violations' => '1',
          'age_18' => 2,
          'dui' => '0',
          'insured' => '1',
          'major' => 0,
          'tickets' => 0

      };
}

sub _build_risk_type {
    
    my($self)=@_;

    my $E =     risk_eval ;
    my %E = %$E;

    warn ('risk criteria - ' . Data::Dumper::Dumper(\%E) ) ;

    $E{age22} && $E{insured} && !$E{sr22} && !$E{dui} && ($E{tickets} 
+<= 1) && !$E{major} and return 'prem' ;
    $E{age18} && $E{insured} && !$E{sr22} && !$E{dui} && $E{tickets} <
+= 3 and return 'std' ;
    $E{age18} and return 'substd';


    die 'No useable risk type found.' 

}

_build_risk_type;

[download]
$E{age22}
equals 2... therefore true
$E{insured}
equals 1 therefore true. && of the 2 conditions means we keep going
!$E{sr22}
equals 1 because we negated the empty string found via $E{sr22} so we keep going in this expression
!$E{dui}
equals 1 because we negate the zero in the hashref
$E{tickets} <= 1
is true because $E{tickets} equals 0
!$E{major}
equals true because major is false
so since each part of the boolean expression returns true, why doesnt the expression  return 'prem' execute and end function execution?

note

the line-wrapping in CODE sections is quite distracting. it adds plus-signs in the middle of expressions.

In reply to boolean chaining - && and 'and' by metaperl

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