What is the equivalent of foreach (with keys) in ActionScript

Question

I am looking for the equivalent of a foreach loop with keys in Actionscript. In PHP this would be:

foreach($array as $key => $value)
{
}

I found two solutions that will work, but I am wondering if there is a better way to do this. The first solution is to use the for..in loop. Which gives you the keys, but you still have to use the key to access the correct element in your structure. For example:

for(var key:String in results)
{
    trace(key + ": " + results[key]);
}

The second option is the for each..in loop, which I believe is new in AS3. With this solution, I can't tell what the keys are. For example:

for each(var row:* in results)
{
    trace(row);
}

For the time being, I am going to use for..in. I am just looking for a better way.

Thanks, Rob

Update: Speed is not a huge deal, because the array is never going to be extremely large. Order does matter, and I would like to get keys in the order of insertion. Here is an example of the array:

sites = {'site1': 34, 'site2': 52, 'site3': 66}

I would like to use the key as well as the value of each entry.

I want to keep my array structure as simple as possible. I could change the sites array above to look like:

sites = {{'name': 'site1', 'id': 34}, 
    {'name': 'site2', 'id': 52},
    {'name': 'site3', 'id': 66}}

However, I would rather not go this route, because it adds more dimensions to my array structure.

Answer 1

It depends on your object type. If you're using a Dictionary, you have:

DictionaryUtil.getKeys(myObject)

I wouldn't use for...in unless you're just dumping or purely want the keys and nothing else. It is an object so sort isn't guaranteed and will vary. If sorting isn't an issue, this (for...in or dictionary) is your best bet.

Grant speaks more on dictionary here: http://www.gskinner.com/blog/archives/2006/07/as3_dictionary.html.

Answer 2

for(var i:String in myArray) // loops through the items in the array
    myArry[i] += 'new message will show'


for each(var i:String in myArray) // creates a copy of the array as it loops
    myArray[i] += 'this change will not show outside the loop';

The later is great for if you need to minipulate the variables during the loop but want to preserve the original object for the rest of your program. Especially handy for formatting or translating values for a specific part of your program.