Question 1

An app can access another app.

Accepted Answer

In some cases, apps can access other apps if they have been granted permission or if they use certain APIs provided by the operating system. However, this access is limited and is usually controlled by the user's settings and preferences.

Question 2

We can test whether the device has a given feature, such as a camera, by calling the hasSystemFeature method of the ____________ class, passing a constant of the class that corresponds to that feature.

Accepted Answer

PackageManager

Question 3

The argb, alpha, red, green, and blue methods of the Color class of the android.graphics package are all static methods.

Accepted Answer

The argb, alpha, red, green, and blue methods of the Color class of the android.graphics package are all static methods, meaning they can be called without instantiating an object of the Color class.

Question 4

The alpha, red, green, and blue methods of the Color class of the android.graphics package all accept one parameter, an int representing a color.

Accepted Answer

The alpha, red, green, and blue methods of the Color class all accept one parameter, an int representing a color.

Question 5

To access programmatically a resource named xyz.xml located in the drawable directory, we use the expression ____________.

Accepted Answer

The answer of To access programmatically a resource named xyz.xml...

Question 6

To set the current value of a seek bar to 0 inside an XML layout file, what attribute do we use?
A) android:current
B) android:value
C) android:progress
D) android:seek

Accepted Answer

The attribute "android:progress" is used to set the initial value for the seek bar to 0. The attribute "android:value" is used to set a specific value for the seek bar, but not necessarily the initial value. The attributes "android:current" and "android:seek" do not exist in the seek bar XML attributes.

Question 7

It is possible to write a method that takes a double parameter and returns that double with a maximum of three significant digits after the decimal point.

Accepted Answer

Yes, it is possible to use the DecimalFormat class in Java to format the double to have a maximum of three significant digits after the decimal point.

Question 8

It is possible for an app to store persistent data on a device.

Accepted Answer

Apps can store persistent data on a device, such as user preferences, login credentials, and app-specific data. This allows the app to remember the user's activities and preferences even after they have closed the app or restarted the device.

Question 9

The fromFile static method of the Uri class takes a File parameter and returns a(n) ____________ reference.

Accepted Answer

The answer of The fromFile static method of the Uri...

Question 10

The createChooser static method of the Intent class returns an Intent reference such that when we start an activity with it, the user is presented with a choice of ____________ that match the Intent.

Accepted Answer

The answer of The createChooser static method of the Intent...

Question 11

The constant that we can pass to the hasSystemFeature to check whether the device includes a camera is ____________.

Accepted Answer

The answer of The constant that we can pass to...

Question 12

After having started an Activity for an Intent by calling the ____________ method, we can access the results inside the onActivityResult method.

Accepted Answer

The answer of After having started an Activity for an...

Question 13

The ____________ of the Bitmap class returns the integer representation of the color of the pixel at coordinate( x, y ) in the Bitmap.

Accepted Answer

The answer of The ____________ of the Bitmap class returns...

Question 14

The ____________ of the Bitmap class sets the color of a point at some x and y coordinate in the Bitmap.

Accepted Answer

The answer of The ____________ of the Bitmap class sets...

Question 15

The onStopTrackingTouch method of the SeekBar.OnSeekBarChangeListener interface is called when the user ____________ touching the seek bar.

Accepted Answer

The answer of The onStopTrackingTouch method of the SeekBar.OnSeekBarChangeListener interface...

Question 16

What constant do we pass to the Intent constructor to create an Intent to use a camera app?
A) MediaStore.IMAGE
B) MediaStore.IMAGE_CAPTURE
C) MediaStore.ACTION_IMAGE_CAPTURE
D) MediaStore.CAMERA

Accepted Answer

The constant that we pass to the Intent constructor to create an Intent to use a camera app is MediaStore.ACTION_IMAGE_CAPTURE. This constant is used to launch the camera app in capture mode and obtain the resulting image. Options A, B, and D do not correspond to the correct constant to use for launching the camera app.

Question 17

What is the name of the class that encapsulates a slider?
A) Slider
B) SeekBar
C) Button
D) CheckBox

Accepted Answer

The class that encapsulates a slider in Android is SeekBar.

Question 18

What is the XML attribute that corresponds to the setMax method of the ProgressBar class?
A) android:max
B) max
C) android:maximum
D) android:setMax

Accepted Answer

The XML attribute that corresponds to the setMax method of the ProgressBar class is android:max. Therefore, the best choice is A.

Question 19

What is the value of the DIRECTORY_PICTURES constant of the Environment class?
A) Directory
B) Photos
C) Pictures
D) Directory_Pictures

Accepted Answer

The value of the DIRECTORY_PICTURES constant of the Environment class is the string "Pictures", so the correct choice is C, Pictures.

Question 20

What is the data type of the only parameter of the setImageBitmap method of the ImageView class?
A) Bitmap
B) ImageBitmap
C) Image
D) ImageView

Accepted Answer

The only parameter of the setImageBitmap method is a Bitmap object, therefore the data type of this parameter is Bitmap.

Quiz 12: Using an Existing App: Taking a Photo and Sending an Email