Android Interview Questions - Intent and Intent Filters

1. What is an Intent?
     Three of the core components of an application — activities, services, and broadcast receivers — are activated through messages, called intents,passive data structure holding an abstract description of an operation to be performed — or, often in the case of broadcasts, a description of something that has happened and is being announced.

2. How will start an Activity?
       startActivity(),startActivityForResult(),setResult()

3. What are the kinds of Intents?
     Implicit Intent and Explicit Intents

4. Explain Explicit and Implicit Intents?
      Explicit intent names the component, e.g. the Java class which should be called.
     Implicit intents asked the system to perform a service without telling the system which Java class should do this service.

5. What is Intent Filters?
   Intent filters are typically defined via the "AndroidManifest.xml" file.where Android system will determine suitable applications for an implicit intent and if several applications exists offer the user the choice to open one.  If a component does not define intent filters it can only be called by explicit intents.

6. What are the object consulted against Intent Filter?
        Action, Data, Category

7.  What is an Action?
    Adds an action to an intent filter. An <intent-filter> element must contain one or more <action> elements. If it doesn't contain any, no Intent objects will get through the filter.
 <intent-filter . . . >
    <action android:name="com.example.project.SHOW_CURRENT" />
    <action android:name="com.example.project.SHOW_RECENT" />
</intent-filter>

8 What is a Category?
Adds a category name to an intent filter. The role of category specifications within a filter.
<intent-filter . . . >
    <category android:name="android.intent.category.DEFAULT" />
    <category android:name="android.intent.category.BROWSABLE" />
    . . .
</intent-filter>

9. What is Data?
Adds a data specification to an intent filter. The specification can be just a data type (the mimeType attribute), just a URI, or both a data type and a URI. A URI is specified by separate attributes for each of its parts:
<intent-filter . . . >
    <data android:mimeType="video/mpeg" android:scheme="http" . . . />
    <data android:mimeType="audio/mpeg" android:scheme="http" . . . />
    . . .
</intent-filter>