perl encapsulate single variable in double quotes

Question

In Perl, is there any reason to encapsulate a single variable in double quotes (no concatenation) ?

I often find this in the source of the program I am working on (w

Answer 1

In your case quotes are completely useless. We can even says that it is wrong because this is not idiomatic, as others wrote.

However quoting a variable may sometime be necessary: this explicitely triggers stringification of the value of the variable. Stringification may give a different result for some values if thoses values are dual vars or if they are blessed values with overloaded stringification.

Here is an example with dual vars:

use 5.010;
use strict;
use Scalar::Util 'dualvar';

my $x = dualvar 1, "2";
say 0+$x;
say 0+"$x";

Output:

1
2