You are viewing the version of this documentation from Perl blead. This is the main development branch of Perl. (git commit b3138094d90d9a1861f0e10af33500f7d508e29c)
$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.