One last time, the facts:
1) There are DOM methods that accept DOMString arguments or return
DOMString values.
Fact.
Sounds like you agree here.
2) In general, such methods need to be able to tell apart null and all
string values (including "" and "null").
They need to determine value type so that they can either throw or
handle. null, 0, undefined, new String('x'), are all not strings.
Sounds like you agree here too?
3) The behavior of null is almost always either that of "" or that of
"null". Which one depends on the exact DOM method.
That is false. null has no behavior. Methods have behavior. For
example, EcmaScript's internal ToString has a behavior of converting
null to "null". That is a behavior.
You aren't actually answering Boris question, but rather point out a
grammatical error in the question. So let me repeat the question with
the grammatical error fixed. Please do excuse any other grammar errors I
introduce as English is a second language to me.
3) The behavior of the function when null is passed as value for an
argument is almost always either that of "" or that of "null".
Which one depends on the exact DOM method.
Do you agree with this?
/ Jonas
