Re: [GeoNetwork-devel] Probable bug in intermap script im_class.js [SEC=UNCLASSIFIED]

[Software I. gn-d. <gn-...@so...>]

Ste...@ga... wrote:
> Flanagan states "undefined is returned when you use either a variable that
> has been declared but never had a value assigned to it or an object property
> that does not exist" - (5th ed.)
> 
> How will your solution behave if for some reason this.north is assigned null?

Haven't tried it.

Flanagan (5th ed.) says on p. 67 in the discussion
of the rules for the == operator:

   -- If one value is null and the other is undefined,
      they are equal.

So maybe testing equality (or non-equality) against
null and against undefined behave (or, should
behave) identically?

Note, === would behave differently from == here;
=== is the "real" comparison operator.
(But the comparison operator should be =, not
== or ===.  Sigh.)

Assuming Flanagan accurately represents
how JS works -- and I have no reason to
doubt that -- I'd say his book is a rich
resource if you're looking for
six impossible things to believe before
breakfast.

-- 
Richard Walker
Software Improvements Pty Ltd
Phone:  +61 2 6273 2055
Fax:  +61 2 6273 2082