You are viewing the version of this documentation from Perl 5.31.3. This is a development release of Perl.
$LIST_SEPARATOR
$"

When an array or an array slice is interpolated into a double-quoted string or a similar context such as /.../, its elements are separated by this value. Default is a space. For example, this:

print "The array is: @array\n";

is equivalent to this:

print "The array is: " . join($", @array) . "\n";

Mnemonic: works in double-quoted context.