Comments on: Loop Safety

By: jackson

jackson — Sun, 19 Jul 2009 02:11:55 +0000

Thanks for this. It’s the subject of post for Friday the 24th.

By: golgobot

golgobot — Sat, 11 Jul 2009 05:43:19 +0000

on that note what would this code trace out?

var dict:Dictionary = new Dictionary();
dict[NaN] = "NaN Real";
dict["NaN"] = "NaN String";
dict[null] = "null Real";
dict["null"] = "null String";
dict[Dictionary] = "Dictionary real";
dict["flash.utils.Dictionary"] = "Dictionary String";
trace(dict[NaN] + ", " + dict[null] + ", " + dict[Dictionary])

When you actually run this code, you’ll be surprised, but not taken aback.

By: jackson

jackson — Fri, 10 Jul 2009 18:00:55 +0000

This is actually in my notes for an upcoming post. I will cover some details of dictionary keys. For example, what kinds of type conversion do you think it does? Consider this:

var dict:Dictionary = new Dictionary();
dict[3] = "hello";
trace(dict["3"]); // what is printed?

By: golgobot

golgobot — Fri, 10 Jul 2009 17:53:31 +0000

That got me to thinking.

What do you think the following code would do?

var dict:Dictionary = new Dictionary();
dict[null] = "null";
dict[undefined] = "undefined";
dict[NaN] = "NaN";
dict[int] = "int";
 
for (var i:* in dict)
{
    trace("dict["+i+"] = " + dict[i]);
}
 
for each (var j:* in dict)
{
    trace("j = " + j);
}

Well apparently it’s all valid. Here’s the output.

dict[null] = null
dict[undefined] = undefined
dict[NaN] = NaN
dict[[class int]] = int
j = null
j = undefined
j = NaN
j = int