use strict;
use warnings;
my $a = 'abcdefg';
print $a,$/;
print substr($a,0,3),$/;       # rvalue (list)
print $a,$/;
print substr($a,0,3)='bob',$/; # lvalue
print $a,$/;
print scalar( substr($a,0,3,'ABC')),$/; # rvalue (scalar)
print $a,$/;
__END__
abcdefg
abc
abcdefg
bob
bobdefg
bob
ABCdefg