Another place where things differ is member variables:
public var a:String;
On the SWF side, this variable defaults to null. On the JS side, it
defaults to undefined right now.
In the case of a member variable, we could set it to null by default on the
JS side to make it more consistent.
For your case, it's a little more tricky, though. Maybe something like
this, if the type on the left side is anything except *? (Numbers and
boolean would need special behavior too, though)
var propA:Object = a.prop || null;
That could have memory or performance implications. Sometimes, trying to
achieve perfect behavior parity can be too expensive. Needs benchmarking
and careful analysis to see if it's worth it, I guess!
- Josh
On Jun 2, 2017 5:20 PM, "Justin Mclean" <jus...@classsoftware.com> wrote:
Hi,
OK the issue is that we getting different results for AS and JS.
For code like this:
var a:Object = {};
var propA:Object = a.prop;
var propB:* = a.prop;
if (propA === undefined) {
trace("A undefined");
}
if (propA === null) {
trace("A null");
}
if (propB === undefined) {
trace("B undefined");
}
if (propB === null) {
trace("B null");
}
On AS we get:
A null
B undefined
On JS we get:
A undefined
B undefined
Which is obvious when you look at the generated code:
var /** @type {Object} */ a = {};
var /** @type {Object} */ propA = a.prop;
var /** @type {*} */ propB = a.prop;
So I’m guessing the compiler should be doing something different with this
line?
var /** @type {Object} */ propA = a.prop;
So it returns null rather than undefined?
Thanks,
Justin
