从数组集合中获取值数组的最简单/最佳方法是什么？

I have an Array Collection with any number of Objects. I know each Object has a given property. Is there an easy (aka "built-in") way to get an Array of all the values of that property in the Collection?

我有一个包含任意数量对象的Array Collection。我知道每个Object都有一个给定的属性。是否有一种简单的(也称为“内置”)方法来获取集合中该属性的所有值的数组?

For instance, let's say I have the following Collection:

例如,假设我有以下集合:

var myArrayCollection:ArrayCollection = new ArrayCollection(
    {id: 1, name: "a"}
    {id: 2, name: "b"}
    {id: 3, name: "c"}
    {id: 4, name: "d"}
    ....
);

I want to get the Array "1,2,3,4....". Right now, I have to loop through the Collection and push each value to an Array. Since my Collection can get large, I want to avoid looping.

我想得到数组“1,2,3,4 ....”。现在,我必须遍历Collection并将每个值推送到Array。由于我的Collection可以变大,我想避免循环。

var myArray:Array /* of int */ = [];

for each (var item:Object in myArrayCollection)
{
    myArray.push(item.id);
}

Does anyone have any suggestions?

有没有人有什么建议?

Thanks.

2 个解决方案

#1

Once you get the underlying Array object from the ArrayCollection using the source property, you can make use of the map method on the Array.

使用source属性从ArrayCollection获取基础Array对象后,可以使用Array上的map方法。

Your code will look something like this:

您的代码将如下所示:

private function getElementIdArray():Array
{
    var arr:Array = myArrayCollection.source;
    var ids:Array = arr.map(getElementId);
    return ids;
}

private function getElementId(element:*, index:int, arr:Array):int 
{
    return element.id;
}

#2

According to the docs the ArrayCollection does not keep the keys separate from the values. They are stored as objects in an underlying array. I don't think there is any way to avoid looping over them to extract just the keys since you need to look at every object in the underlying array.

根据文档,ArrayCollection不会将键与值分开。它们作为对象存储在底层数组中。我不认为有任何方法可以避免循环它们只提取键,因为你需要查看底层数组中的每个对象。

#1