Android

Q1. To add features, components, and permissions to your Android app, which file needs to be edited?

AndroidManifest.xml
Components.xml
AppManifest.xml
ComponentManifest.xml

Q2. Which XML attribute should be used to make an Image View accessible?

android:talkBack
android:labelFor
android:hint
android:contentDescription

Q3. You launch your app, and when you navigate to a new screen it crashes, Which action will NOT help you diagnose the issue?

Set breakpoints and then step through the code line by line
Use the profiler tools in Android Studio to detect anomalies CPU, and network usage.
Add a Thread.sleep()call before you start the new activity.
inspect the logs in Logcat.

Q4. Why might push notifications stop working?

all of these answers
The device token is not being sent to push provider correctly.
Google Play Services is not installed on the deivce/emulator.
Battery optimization is turned on on the device.

Q5. What is the correct set of component classes needed to implement a RecyclerView of items that displays a list of widgets vertically?

[ ]

      RecycleView
      RecyclerView.Adapter<T extends BaseAdapter>
      RecyclerView.ViewHolder<T extends BaseViewHolder>
      LinearLayoutManager

[ ]

      RecycleView
      RecyclerView.Adapter
      RecyclerView.ViewHolder<T extends BaseViewHolder>
      LinearLayoutManager

[ ]

      RecycleView
      RecyclerView.Adapter
      RecyclerView.ViewHolder
      LinearLayoutManager

[x]

      RecycleView
      RecyclerView.Adapter<VH extends ViewHolder>
      RecyclerView.ViewHolder
      LinearLayoutManager

Q6. The Android system kills process when it needs to free up memory. The likelihood of the system killing a given process depends on the state of the process and the activity at the time. With combination of process and activity state is most likely to be killed?

Process:In the background;Activity:Is stopped
Process:In the background;Activity:Is paused
Process:In the foreground;Activity:Is started
Process:In the foreground;Activity:Is paused

Q7. You have created a NextActivity class that relies on a string containing some data that pass inside the intent Which code snippet allows you to launch your activity?

[ ]

        Intent(this, NextActivity::class.java).also { intent ->
            startActivity(intent)
        }

[ ]

        Intent(this, NextActivity::class.java).apply {
            put(EXTRA_NEXT, "some data")
        }.also { intent ->
            activityStart(intent)
        }

[x]

        Intent(this, NextActivity::class.java).apply {
            putExtra(EXTRA_NEXT, "some data")
        }.also { intent ->
            startActivity(intent)
        }

[ ]

        Intent(this, NextActivity::class.java).apply {
            put(EXTRA_NEXT, "some data")
        }.also { intent ->
            activityStart(intent)
        }

Q8. You want to include about and setting modules in your project. Which files accurately reflects their inclusion?

in build.gradle:include ':app',':about' ':settings'
in settings.gradle:include ':app',':about' ':settings'
in settings.gradle:include ':about',':settings'
in gradle.properties:include ':app',':about' ':settings'

Q9. What is the benifit of using @VisibleForTesting annotation?

to denote that a class, methos, or field has its visibility relaxed to make code testable
to denote that a class, method, or field is visible only in the test code
to denote that a class, method, or field has its visibility increased to make code less testable
to throw a run-time error if a class, methos, or field with this annotation is accessed improperly

Q10. How would you specify in your build.gradle file that your app required at least API level 21 to run, but that it can be tested on API level 28?

[ ]

      defaultConfig {
        ...
        minApiVersion 21
        targetApiVersion 28
      }

[ ]

      defaultConfig {
        ...
        targetSdkVersion 21
        testSdkVersion 28
      }

[ ]

      defaultConfig {
        ...
        minSdkVersion 21
        testApiVersion 28
      }

[x]

      defaultConfig {
        ...
      minSdkVersion 21
        targetSdkVersion 28
      }

Q11. When will an activity's onActivityResult()be called?

when calling finish()in the parent activity
when placing an app into the background by sitching to another app
When onStop() is called in the target activity
when calling finish() in the target activity

For more information

Q12. You need to remove an Event based on it;s id from your API, Which code snippet defines that request in Retrofit?

@DELETE("events) fun deleteEvent(@Path("id") id: Long): Call
@DELETE("events/{id}") fun deleteEvent(@Path("id") id: Long): Call
@REMOVE("events/{id}") fun deleteEvent(@Path("id") id: Long): Call
@DELETE("events/{id}") fun deleteEvent(@Path("id") id: Long): Call

Q13. When would you use a product flavour in your build setup?

when you need to have the app's strings present in multiple lanuages
when you have to provide different versions of your app based on the physical device size
when you want to provide different versions of your app based on the device screen density
when you want to provide different version of your app with custom configuration and resources

Q14. Given the fragment below, how would you get access to a TextView with an ID of text_home contained in the layout file of a Fragment class?

    private lateinit var textView: TextView
    override fun onCreateView(...): View? {
        val root = inflator.inflator(R>layout.fragment_home, container, false)
        textView = ??
        return root
    }

root.getById(R.id.text_home)
findViewByID(R.id.text_home)
root.findViewById(R.id.text_home)
root.find(R.id.text_home)

Q15. Why do you use the AndroidJUnitRunner when running UI tests?

The test runner facilitates loading your test package and the app under test onto a device or emulator, runs the test, and reports the results.
The test runner creating screenshots of each screen that displayed while tests are executed.
The test runner facilitates parallelization of test classes by providing for each test class.
The test runner facilitates interacting with visible elements on a device, regardless of the activity or fragment that has focus.

Q16. What allows you to properly restore a user's state when an activity is restarted?

the onSaveInstance()method
all of these answers
persistent storage
ViewModel objects

Q17. Given the definition below. how would you get access a TextView with an ID of text_home contained in thr layout file of a Fragment class?

root.find(R.id.text_home)
findViewById(R.id.text_home)
root.getById(R.id.text_home)
root.findViewById(R.id.text_home)

Q18. IF the main thread is blocked for too long, the system displays the _ dialog?

Thread Not Responding
Application Paused
Application Not Responding
Application Blocked

Q19. How would you retrieve the value of a user's email from SharedPreferences while ensuring that the returned value is not null?

getPreferances(this).getString(Email,"")
getDefaultSharedPrefarances(this).getString(EMAIL,null)
getDefaultSharedPreferances(this).getString(EMAIL,"")
getPreferances(this).getString(EMAIL,null)

Explanation: In Method "getDefaultSharedPrefarances(this).getString()" Second parameter is passed so that it can be returned, in case key doesn't exist. So we need to pass an empty string to be returned in case key doesn't exist.

Q20. Why is it problematic to define sizes using pixels on Android?

Although screen pixel density varies, this does not impact the use of pixels to define sizes.
Large devices always have more pixels, so your UI elements will be e=affected if you define them with pixels.
The same number of pixels may correspond to different physical sizes, affecting the appearance of your UI elements.
Different devices have different understanding of what a pixel is , affecting the appearance of your UI elements

Q21. You need to get a list of devices that are attached to your computer with USB debugging enable. Which command would execute using the Android Debug Bridge?

list devices
adb devices
list avd
dir devices

Q22. Which drawable definition allows you to achieve the shape below?

[ ]

    xml
    <shape xmlns:android="http://schemas.android.com/apk/res/android"
        android:shape="oval">
        <stroke
            android:width="4dp"
	    android:color="@android:color/white" />
	<solid android:color="@android:color/black" />
    </shape>

[ ]

    xml
    <oval xmlns:android="http://schemas.android.com/apk/res/android">
        <stroke android:width="4dp" android:color="@android:color/black"/>
        <solid android:color="@android:color/white"/>
    </oval>

[x]

    xml
    <shape xmlns:android="http://schemas.android.com/apk/res/android"
        android:shape="oval">
        <stroke
            android:width="4dp"
            android:color="@android:color/black" />
        <solid android:color="@android:color/white" />
    </shape>

[ ]

    xml
    <shape xmlns:android="http://schemas.android.com/apk/res/android"
        android:shape="oval">
        <stroke
            android:width="4dp"
            android:color="@android:color/white" />
        <solid android:color="@android:color/white" />
    </shape>

Q23. To persist a small collection of key-value data, what should you use?

external file storage
SharedPereferences
SQLite
internal file storage

Q24. You need to retrieve a list of photos from an API. Which code snippet defines an HTML GET request in Retrofit?

@GET("photo/{id}"} fun listPhotos(@Path("id") id:Long?) : Call
@LIST("photo") fun listPhotos() : Call<List>
@GET("photo") fun listPhotos() : Call
@GET("photo") fun listPhotos() : Call<List>

Q25. Given the test class below, which code snippet would be a correct assertion?

assertThat(resultAdd).is(2.0)
assertNotNull(resultAdd)
assertThat(resultAdd).isWqualTo(2.0)
assertThat(resultAdd)

Q26. What tag should you use to add a reusable view component to a layout file?

<merge/>
<include/>
<layout/>
<add/>

Q27. You want to provide a different drawable for devices that are in landscape mode and whose language is set to French. which directory is named correctly?

fr-land-drawable
drawable-fr-land
drawable-french-land
french-land-drawable

Q28. Why might you need to include the following permission to your app?

android.permission.ACCESS_NETWORK_STATE

to monitor the location of the devices so that you don't attempt to make network calls when the user is stationary
to request the ability to make network calls from your app
to monitor the network state of the device so that you can display an in-app banner to the user
to monitor the network state of the devices so that you don't attempt to make network calls when the network is unavailable

Q29. Which image best corresponds to the following `LinearLayout`?

    xml
    <LinearLayout
        android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:orientation="horizontal"
	android:gravity="center">
	<Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button" />
	<Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button" />
        </LinearLayout>

A
B
C
D

Q30. You want to open the default Dialer app on a device. What is wrong with this code?

val dialerIntent = Intent()
val et = findViewById(R.id.some_edit_text)
dialerIntent.action = Intent.ACTION_DIAL
dialerIntent.data = Uri.parse("tel:" + et.getText()?.toString())
startActivity(dialerIntent)

startActivityWithResult() should be used instead of startActivity() when using Intent.ACTION_DIAL.
For Intent.ACTION_DIAL, the Intent option Intent.FLAG_ACTIVITY_NEW_TASK must be added when using this dialerIntent.
The dialerIntent will cause an ActivityNotFoundException to be thrown on devices that do not support Intent.ACTION_DIAL.
The permission android.permission.CALL_PHONE must be requested first before Intent.ACTION_DIAL can be used.

Q31. When should you store files in the `/assets` directory?

when you need access to the original file names and file hierarchy
when you need access to the file with its resource ID, like R.assets.filename
when you have XML files that define tween animations
when you need to access the file in its raw form using Resources.openRawResource()

Q32. You want to allow users to take pictures in your app. Which is not an advantage of creating an appropriate `intent`, instead of requesting the camera permission directly?

Users can select their favorite photo apps to take pictures.
You do not have to make a permission request in your app to take a picture.
You have full control over the user experience. The app that handles the camera intent will respect your design choices.
You do not have to design the UI. The app that handles the camera intent will provide the UI.

Q33. When would you use the `ActivityCompat.shouldShowRequestPermissionRationale()` function?

when a user first opens your app and you want to provide an explanation for the use of a given permission
when a user has previously denied the request for a given permission and selects "Tell me more"
when a user has previously denied the request for a given permission and you want to provide an explanation for its use
when a user has previously denied the request for a given permission and selected "Don't ask again," but you need the permission for your app to function

Q34. You would like to enable analytics tracking only in `release` builds. How can you create a new field in the generated `BuildConfig` class to store that value?

[ ]

buildTypes {
	debug {
		buildConfig 'boolean', 'ENABLE_ANALYTICS', 'false'
	}
	release {
		buildConfig 'boolean', 'ENABLE_ANALYTICS', 'true'
	}
}

[ ]

buildTypes {
	debug {
		buildConfig 'String', 'ENABLE_ANALYTICS', 'false'
	}
	release {
		buildConfig 'String', 'ENABLE_ANALYTICS', 'true'
	}
}

[x]

buildTypes {
	debug {
		buildConfigField 'boolean', 'ENABLE_ANALYTICS', 'false'
	}
	release {
		buildConfigField 'boolean', 'ENABLE_ANALYTICS', 'true'
	}
}

[ ]

buildTypes {
	debug {
		buildConfigField 'boolean', 'ENABLE_ANALYTICS', 'true'
	}
	release {
		buildConfigField 'boolean', 'ENABLE_ANALYTICS', 'false'
	}
}

Q35. To optimize your APK size, what image codec should you use?

JPG
PNG
MPEG
WebP

Q36. You have built code to make a network call and tested that it works in your development environment. However, when you publish it to the Play console, the networking call fails to work. What will not help you troubleshoot this issue?

checking whether ProGuard -keepclassmembers have been added to the network data transfer objects (DTOs) in question
using the profiler tools in Android Studio to detect anomalies in CPU, memory, and network usage
checking for exceptions in the server logs or server console
checking that the network data transfer object has @SerizlizedName applied to its member properties

Q37. Which code snippet would achieve the layout displayed below?

[ ]

xml
    <androidx.constraintlayout.widget.ConstraintLayout
	...>

	<TextView
		android:id="@+id/text_dashboard"
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:layout_marginTop="16dp"
		android:padding="8dp"
		android:textAlignment="center"
		android:text="Dashboard"
		app:layout_constraintEnd_toEndOf="parent"
		app:layout_constraintStart_toStartOf="parent"
		app:layout_constraintTop_toTopOf="parent" />

    </androidx.constraintlayout.widget.ConstraintLayout>

[x]

xml
    <androidx.constraintlayout.widget.ConstraintLayout
	...>

	<TextView
		android:id="@+id/text_dashboard"
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:layout_marginStart="8dp"
		android:layout_marginEnd="8dp"
		android:textAlignment="center"
		android:text="Dashboard"
		app:layout_constraintEnd_toEndOf="parent"
		app:layout_constraintStart_toStartOf="parent"
		app:layout_constraintTop_toTopOf="parent" />

    </androidx.constraintlayout.widget.ConstraintLayout>

[ ]

xml
    <androidx.constraintlayout.widget.ConstraintLayout
	...>

	<TextView
		android:id="@+id/text_dashboard"
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:layout_marginStart="8dp"
		android:layout_marginTop="16dp"
		android:layout_marginEnd="8dp"
		android:padding="8dp"
		android:textAlignment="center"
		android:text="Dashboard"
		app:layout_constraintEnd_toEndOf="parent"
		app:layout_constraintStart_toStartOf="parent"
		app:layout_constraintTop_toTopOf="parent" />

    </androidx.constraintlayout.widget.ConstraintLayout>

[ ]

xml
    <androidx.constraintlayout.widget.ConstraintLayout
	...>

	<TextView
		android:id="@+id/text_dashboard"
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:layout_marginStart="8dp"
		android:layout_marginTop="16dp"
		android:layout_marginEnd="8dp"
		android:padding="8dp"
		android:text="Dashboard"
		app:layout_constraintEnd_toEndOf="parent"
		app:layout_constraintStart_toStartOf="parent"
	/>

</androidx.constraintlayout.widget.ConstraintLayout>

Q38. Which source set is `_not_` available to you by default when Android Studio creates a new project?

test
androidTest
app
main

Q39. Which definition will prevent other apps from accessing your `Activity` class via an `intent`?

[x]

xml
	<activity android:name=".ExampleActivity" />

[ ]

xml
	<activity android:name=".ExampleActivity">
		<intent-filter>
			<action android:name="android.intent.action.SEND" />
		</intent-filter>
	</activity>

[ ]

xml
	<activity android:name=".ExampleActivity">
		<intent-filter>
			<action android:name="android.intent.action.MAIN" />
			<category android:name="android.intent.category.LAUNCHER" />
		</intent-filter>
	</activity>

[ ]

xml
	<activity android:name=".ExampleActivity">
		<intent-filter>
			<action android:name="android.intent.action.VIEW" />
		</intent-filter>
	</activity>

Explanation: Intent filters are used to make activities accessible to other apps using intents. So we have to choose option which have no intent filter to make sure it is not accessible by intent

Q40. To preserve on-device memory, how might you determine that the user's device has limited storage capabilities?

Use the ActivityManager.isLowRamDevice() method to find out whether a device defines itself as "low RAM."
Use the Activity.islowRam() method to find out whether a device defines itself as "low RAM."
Use the ConnectivityManager.hasLowMemory() method to find out whether a device defines itself as "low RAM."
Make an image download request and check the remaining device storage usage.

Q41. What is `_not_` a good way to reuse Android code?

Use a common Gradle module shared by different Android projects.
Prefer to build custom views or fragments over activities.
Prefer to build activities instead of fragments.
Break down UI layouts into common elements and use <include/> to include them in other layout XML files.

Q42. Which layout is best for large, complex hierarchies?

LinearLayout
ConstraintLayout
FrameLayout
RelativeLayout

Q43. You need to upgrade to the latest version of the Android Gradle plugin. Which file should you modify?

root_project_dir/app/build.gradle.
root_project_dir/settings.gradle.
root_project_dir/build.gradle.
root_project_dir/app/gradle.properties.

reference

Q44. Why do developers often put app initialization code in the Application class?

The Application class is instantiated before any other class when the process for the application is created.
The Application class is instantiated after any permissions requests when the process for the application is created.
The Application class is created each time a new Activity is launched, making it ideal for initialization code.
The Application class is created each time a background service is called, making it ideal for initialization code.

reference

Q45. What folder should you use for your app's launcher icons?

/drawable
/icon
/mipmap
/launcher

Q46. Which drawable definition allows you to achieve the shape below?

[ ]

xml
	<shape xmlns:android-"http://schemas.android.com/apk/res/android"
	    android:shape-"oval">
	    <gradient
               android:startColor-"@android:color/white"
               android:endColor-"@android:color/black"
               android:angle-"45"/>
	</shape>

[ ]

xml
	<rectangle xmlns:android-"http://schemas.android.com/apk/res/android">
	   <gradient
	      android:startColor-"@android:color/white"
	      android:endColor-"android:color/black"
	      android:angle-"135"/>
	</rectangle>

[ ]

xml
	<shape xmlns:android-"http://schemas.android.com/apk/res/android"
	   android:shape-"rectangle">
	   <gradient
	      android:startColor-"@android:color/white"
	      android:endColor-"@android:color/black"
	      android:angle-"135"/>
	</shape>

[ ]

xml
	<shape xmlns:android-"http://schemas.android.com/apk/res/android"
	   android:shape-"rectangle">
	   <gradient
	      android:startColor-"@android:color/white"
	      android:endColor-"@android:color/black"
	      android:angle-"98"/>
	</shape>

Q47. Given the ConstraintLayout below, which statement is true?

View B is not horizontally constrained.
View C has too many constraints.
View B is not vertically constrained.
View C is constrained to the parent.

Q48. Given this code snippey from a build.gradle file, which choice is not a possible build variant?

android {
    ...
    defaultConfig{...}

    buildTypes{
    debug{...}
    releasae{...}
}

  flavorDimensions "environment"
  productFlavors {
     producation {...}
     staging {...}
  }
}

productionDebug.
developmentDebug.
stagingDebug.
stagingRelease.

Reference

Q49. When should you use the androidTest directory to store your test classes?

when the tests consist only of unit tests.
when the number of tests to run is large(500+).
when the tests need to run on your local machine.
when the tests need to run on real or virtual devices.