sub get_max_index {  #revisit how to define functions/"my" var ? (default parameters?)
    my $imax=0;
    for (my $i=0; $i<@_; $i++)
         { 
           $imax=$_[$i] if ($imax<=$_[$i]);}
    return $imax;
}

##</code><code>##

use strict;
use warnings;

sub get_max_index {  

    my (@copyOfArray) = @_;  #make an explicit local copy
    
    my $imax= shift @copyOfArray;  # modifies this copy, but ok
    
    for (@copyOfArray){            # no indices...
        $imax = $_ if $imax < $_;
    }
    return $imax;    
}


my @arr = (1..10);
my $ans = get_max_index(@arr);
print"$ans\n";

##</code><code>##

use strict;
use warnings;


sub get_max_index
{
    my $arrayRef = shift;
    
    my $imax = $arrayRef->[0]; #don't modify @arr
    
    for (@$arrayRef){
            $imax = $_ if $imax < $_;
        }
    return $imax;  
}

my @arr = (1..10);
my $ans = get_max_index(\@arr);  #pass reference to array!
print"$ans\n";