Android

Question 1

What are the four types of app components?

Answer 1

Activities
Services
Broadcast Receivers
Content Providers

Question 2

What is an activity?

Answer 2

An activity is the entry point for interacting with the use. It represents a single screen with a user interface.

Question 3

An activity is ___________ as a _________ of the ____________ class.

Answer 3

An activity is implemented as a subclass of the Activity class.

Question 4

What is a content provider?

Answer 4

The interface to data saved in a structured format. A content provider manages a shared set of app data that you can store in the file system

Question 5

What is a service?

Answer 5

A general purpose entry point for keeping an app running in the background for all kinds of reasons. It does not provide a user interface

Question 6

A service is ____________ as a subclass of ________________

Answer 6

A service is implemented as a subclass of Service.

Question 7

What is a broadcast receiver?

Answer 7

A broadcast receiver is a component that enables the system to deliver events to the app outside of a regular user flow, allowing the app to respond to system-wide broadcast announcements.

Question 8

a broadcast receiver is implemented a subclass of ______________ and each broadcast is delivered as an _____ object.

Answer 8

A broadcast receiver is implemented as a subclass of BroadcastReceiver and each broadcast is delivered as an Intent object.

Question 9

Activities, services, and broadcast receivers are activated by an asynchronous message called an ___________

Answer 9

Intent

Question 10

What are Intents?

Answer 10

Intents are messengers that request an action from other components, whether the component belongs to your app or another.

Question 11

What are the two types of intents?

Answer 11

Explicit & implicit intents. Explicit intent defines a message to activate a specific component. Implicit intent defines a message to activate a specific type of components.

Question 12

Content providers are activated when targeted by a request from a __________________.

Answer 12

ContentResolver

Question 13

What are the methods to start an activity or give it something new to do?

Answer 13

You can start an activity or give it something new to do by passing an Intent to startActivity() or startActivityForResult() (when you want the activity to return a result).

Question 14

How can you initiate a broadcast?

Answer 14

You can initiate a broadcast by passing an Intent to methods such as sendBroadcast(), sendOrderedBroadcast(), or sendStickyBroadcast().

Question 15

(API 21+) The JobScheduler can be used to schedule actions. Previously you can start a service (or give new instructions to an ongoing service) by….

Answer 15

passing an Intent to startService(). You can bind to the service by passing an Intent to bindService(). (Must use Explicit Intent and do no declare intent filters for your services).

Question 16

You can perform a query to a content provider by calling ________ on a ______________

Answer 16

by calling query() on a ContentResolver.

Question 17

The primary task of the manifest is …..

Answer 17

The primary task of the manifest is to inform the system about the app’s components.

Question 18

The manifest does a number of things in addition to declaring the app’s components, such as the following four:

Answer 18

1) User permissions,
2) Minimum API, 3) hardware/software features used/required,
4) API libraries (e.g. Google Maps libary).

Question 19

What series of callbacks are used to handle transitions between states of an activity lifecycle?

Answer 19

onCreate()
onStart()
       onResume()
onPause()
        onStop()
onRestart() or onDestroy()

Question 20

Most of an app’s core functionality is implemented in the __________ method.

Answer 20

onResume()

Question 21

What callbacks follow onPause() ?

Answer 21

onStop() or onResume()

Question 22

What callbacks follow onStop()?

Answer 22

onRestart() or onDestroy()

Question 23

During what callbacks is an activity visible to the user?

Answer 23

onStart()
onResume()
onPause() partially visible