Your code does not compile, and does not make sense. (Your communication also leaves a lot to the imagination.)

Try this code instead:

use strict;
use warnings;
my ($i , $j);
$i = 1;
$j = $i - 1;
sub bca{
     $i = $i+1;
     $j = $j+1;
}
print "Before SUB call \$i=$i\n";
bca();
print "After  SUB call \$i=$i\n";
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