Ans:

ArrayCollection:

The ArrayCollection class is a wrapper class that exposes an Array as a collection that can be accessed and manipulated using the methods and properties of the ICollectionView or IList interfaces. Operations on a ArrayCollection instance modify the data source; for example, if you use the removeItemAt() method on an ArrayCollection, you remove the item from the underlying Array.

For example:

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
               xmlns:s="library://ns.adobe.com/flex/spark" 
               xmlns:mx="library://ns.adobe.com/flex/mx" 
               minWidth="955" minHeight="600">
    <s:layout>
        <s:VerticalLayout/>
    </s:layout>
    <fx:Script>
        <![CDATA[
            private function gridinitialize():void {
                data.dataProvider = [
                    {aName:'Bikrant', DOB:'01/01/1986', 
                        City:'Delhi', State:'NewDelhi'},
                    {aName:'Brijesh', DOB:'15/07/1984', 
                        City:'Noida', State:'Uttar Pradesh'},
                    {aName:'Gaurav', DOB:'27/06/1989', 
                        City:'Mumbai', State:'Maharashtra'}                 
                ];
            }
        ]]>
    </fx:Script>
    <s:Panel title="DataGrid Control Example" width="428" height="409">
        <mx:DataGrid id="data" 
                     initialize="gridinitialize()" 
                     x="12" y="12" 
                     borderColor="#000000" 
                     borderStyle="solid" 
                     chromeColor="#000000" 
                     color="#90BB2A" 
                     fontFamily="verdana" 
                     fontGridFitType="pixel" 
                     symbolColor="#FFFFFF" 
                     textAlign="center"/>

    </s:Panel>  
</s:Application>

Array:

The Array class lets you access and manipulate arrays. Array indices are zero-based, which means that the first element in the array is [0], the second element is [1], and so on. To create an Array object, you use the new Array() constructor . Array() can also be invoked as a function. In addition, you can use the array access ([]) operator to initialize an array or access the elements of an array.

For example:

<?xml version="1.0"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
    xmlns:s="library://ns.adobe.com/flex/spark" 
    xmlns:mx="library://ns.adobe.com/flex/mx">

    <fx:Script>
        <![CDATA[
            [Bindable]
            public var myArray:Array = ["Delhi", "Mumbai", "Chennai"]; 
        ]]>
    </fx:Script>

    <mx:ComboBox id="myCB0" dataProvider="{myArray}"/> 
</s:Application>