2.1.3.5 Characters Requiring Special Consideration
The final issue we have yet to address with double-quoted strings is the
use of `$' and `@'. These two characters must always be
quoted. The reason for this is not apparent now, but be sure to keep
this rule in mind until we learn why this is needed. For now, it is
enough to remember that in double-quoted strings, Perl does something
special with `$' and `@', and thus we must be careful to
quote them. (If you cannot wait to find out why, you should read
2.3.1 Scalar Interpolation and 3.4.4 Array Interpolation.
