Flex Interview Questions

1) What is Flex?
Flex is used to devleop Rich Internet Application (RIA) You can both desktop & web based applicaiton.It is markup language and object-oriented languages its many syntax match with flash action script. Flex Developers use typically five distinct phases to develoep Rich Internet Application.

• Design
• Configure
• Build
• Deploy
• Secure

2) How do i get Page URL and Query String ?
We can use mx.core.Application.application.url (mx.core)package to work with current page URL. & query string.


3) Describe flex component file types ?
There are following file types we can use in flex.

• extension .mxml - a component implemented as an MXML file.
• extension .as - a component implemented as an ActionScript class.
• extension .swc - a SWC file contains components in a packge.

4) Difference between target & currentTarget ?

• target : This property is set by the dispatchEvent() method. You cannot change this to a different object.
• currentTarget : This property is set by component instance that is actively processing the event object.
  

5) How many type of components you can create in action script?
We can create two type of components using action script, which are as follows.

• User-interface, or visual, components
• Nonvisual components

6) What's MXML Components ?
MXML components are MXML files that is use in other mxml files just like a MXML tags. One of the main uses of MXML components is to extend the functionality of an existing Flex component & reusebility of custom components.

7) How many type of metadata tags can use in flex ?
Following metadata tags we can you in flex.

• [Inspectable] - use to define an attribute exposed to component users in the attribute hints and Tag inspector.
• [DefaultProperty] - use to define default property.
• [Effect] - use to define effect.
• [Embed] - use to import JPEG, GIF, PNG, SVG, and SWF files at compile time.
• [ArrayElementType] - use for an Array.
• [Bindable] - use to identify a property that you use tags
• [IconFile] - use to identify icon file.
• [Event] - use to define an event.
• [NonCommittingChangeEvent] - use to identify an event as an interim trigger.
• [Style] - use to define the MXML property for a style property.
• [InstanceType] - use to specify the allowed data type of a property.

8) What is Metadata tags in flex ?
Metadata tags provide information to the Flex compiler that describe to flex compiler how your components
are used in a Flex application.

For example,

[Event(name="creationComplete", type=flash.events.Event)]


9) What is trace method ?
Trace is used to print value of variables in small window it is also refer as console output. It is basically used to testing variables or objects value.

For examples,

trace("show msg..");

How can we add styles in run time ?
We can use setStyle() method to add style in run time.

for exmaples,

Component.setStyle("backgroundColor","red");

10) Which methods we can use to retrive and send data using HTTPService (HTTP Request) in flex ?
We can use following methods in HTTPService.

• GET
• POST
• DELETE
• OPTIONS
• TRACE
• PUT
• HEAD

11) What is ArrayCollection?
Array Collection is the type of associate array. This is also called multi array where we can store different kinds of data type link string, integer etc. We can use Array Collection to make datagrid dataset & also use in other components to display related data.


12) How to handle navigation in flex ?
This can be handle using states. for calling different states we can create links and jump that particular state also can remove/add child at run time.

13) What type of Application we can build in flex ?

14) What is the difference between applet & flex web application ?

15) Which one the best web application applet or flex?

16) What are the common features in java & flex?

17) How can we store temporary variable in flex air application?

18) How do we pass variables from flex to JavaScript?

19) What is procedure to define dispatch event in flex?

20) What is the difference between HTTPService and Data Service?

21) How can you write to the file system from flex air application?

22) What is the difference between flex & flash ?