2.8.12.1.2 writeln ([ item1 [, item2 [, …]]]))

If a host-dependent debugging facility is available, ToString is called once, in order, on each item argument. The result of the call is passed to the debugging facility with the intent that the result be output to the user without the insertion of any line terminator characters between item results. A line terminator should be output after the last item or if there are no item arguments. The function returns undefined regardless of whether a debugging facility is present.

The length property of the write function is 0.