请问这段脚本中$" = "\n"是什么语法

#!/usr/bin/perl
# Fig 6.7: fig06_07.pl
# Demonstrating a subroutine that returns a scalar or a list.
# call scalarOrList() in list context to initialize @array,
# then print the list
@array = scalarOrList(); # list context to initialize @array
$" = "\n";                # set default separator character
print "Returned:\n@array\n";
# call scalarOrList() in scalar context and concatenate the
# result to another string
print "\nReturned: " . scalarOrList(); # scalar context
# use wantarray to return a list or scalar
# based on the calling context
sub scalarOrList
{
   if ( wantarray() ) {   # if list context
      return 'this', 'is', 'a', 'list', 'of', 'strings';
   }
   else {               # if scalar context
      return 'hello';
   }
}

$" = "\n";                # set default separator character
它是个全局变量，数组插入字符串时分隔元素的东西。perlvar

双引号中的array的元素的分隔符 print的时候。

谢谢，明白了