Perl 5 version 32.0
                        documentation
                    
                    join
  
- join EXPR,LIST
Joins the separate strings of LIST into a single string with fields
separated by the value of EXPR, and returns that new string.  Example: -    my $rec = join(':', $login,$passwd,$uid,$gid,$gcos,$home,$shell);
 
 Beware that unlike split,
join doesn't take a pattern as its first argument.
Compare split.