Engineering Maintainable Android Apps Coursera Quiz Answers

Get All Weeks Engineering Maintainable Android Apps Coursera Quiz Answers

Engineering Maintainable Android Apps, which is a 4 week MOOC that shows by example various methods for engineering maintainable Android apps, including test-driven development methods and how to develop/run unit tests using JUnit and Robotium (or equivalent automated testing frameworks for Android), as well as how to successfully apply common Java/Android software patterns to improve the extensibility and clarity of Android apps.

Students will work on the appropriate automated unit quizzes, based on the material covered in the lecture videos. These lessons will demonstrate the benefits of good software engineering practices that are targeted at creating maintainable code for mobile apps.

There will be roughly 3-4 hours of student engagement time per week, including video lectures, and quizzes. The ordering of the modules within the course is designed to be flexible.

In particular, students can watch the videos in whatever order suits their experience and needs, e.g., they may want to watch the unit testing videos prior to the software pattern videos if they prefer to learn about unit testing first.

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Week 1: Engineering Maintainable Android Apps Coursera Quiz Answers

Quiz 1: Testing I Quiz

Q1. Which of the following are reasons to write tests (select all that apply)?

to ensure that new functionality operates as expected
to make apps run faster by reducing binary sizes
to help make sure that changes to code do not break existing functionality
to measure how effective software developers are

Q2. When building a new app, which of the following are true (select all that apply)?

There is exactly one way to implement it.
Finding the right design may be an iterative process.
Measuring the impact of changes is critical.
There is exactly one way to design it.

Q3. What is a unit test (select all that apply)?

a test that isolates a specific component for evaluation
a test that isolates multiple components for evaluation
a measurement of test coverage
a test that measures performance
a test of a single user interface element

Q4. Which Java framework is used to write unit tests in Android (select all that apply)?

Retrofit
Apache Commons
JUnit
Dagger
Android

Q5. Why is it important for unit tests to run quickly (select all that apply)?

to ensure that user interface components are not slowed down
to minimize the time developers wait for feedback on their code changes
to avoid blocking the main thread in an Android app
to minimize the number of mistakes that developers make
to minimize the startup time of the Android emulator

Q6. Which of the following is a valid, although not useful, JUnit test (select all that apply)?

123 public void test() { ensureTrue(true); }
1234 @Unit public void test() throws Exception { assert(true == true); }
1234 @Test public void ensureTrue() { assertEquals(true, true); }
1234 @Unit public void ensureTrue() { assertEquals(true,true); }
1234 @Testpublic void test() { ensure.that(true); }

Q7. Which of the following is not an appropriate way to setup the state for MyObject in the test below (select all that apply)?

123456 private MyObject myObject = new MyObject();

@Test public void testInitialName() { assertEquals(“bob”, myObject.getName());}

123456789101112 private MyObject myObject;

@Test public void testInitialName() { myObject = new MyObject(); assertEquals(“bob”, myObject.getName());}

@Test public void testInitialSize() {

1234567891011 private MyObject myObject;

@Before public void setUp(){ myObject = new MyObject(); }

@Test public void testInitialName() { assertEquals(“bob”, myObject.getName());

12345678910111213141516 private MyObject myObject;

@Before public void setUp(){ myObject = new MyObject ();}

@Test public void testInitialName() {assertEquals(“bob”, myObject.getName());

1234567891011 private MyObject myObject = new MyObject();

@Test public void testInitialName() { assertEquals(“bob”, myObject.getName()); }

@Test public void testInitialSize() { assertEquals(10, myObject.getSize());

Q8. Assume that the MyObject.dangerous() function throws a checked exception. Which of the following are valid ways to write a test of MyObject (select all that apply).

12345 @Unit public void someTest() throws Exception { MyObject obj = new MyObject(); assertEquals(false, obj.dangerous()); }
1234567 @Test public void someTest() { MyObject obj = new MyObject(); try{ assertEquals(false, obj.dangerous()); }catch(Exception e){ e.printStackTrace(); } }
12345 @Test public void someTest() throws Exception { MyObject obj = new MyObject(); assertEquals(false, obj.dangerous()); }
12345 @Test public void someTest() { MyObject obj = new MyObject(); assertEquals(false, obj.dangerous()); }
1234567 @Test public void someTest() {MyObject obj = new MyObject(); try{ assertEquals(false, obj.dangerous()); }catch(Exception e){} }

Q9. What are valid uses of code coverage metrics (select all that apply)?

to determine where more testing may be needed
to guarantee that an app is bug free
to evaluate the quality of a development team
to determine if an app has been tested sufficiently
techniques to help developers test faster

Q10. Which of the following are true about the test shown below (select all that apply):

12345678910111213

public class SomeTest {

private MyObject myObject = new MyObject();

@Test

public void testInitialName() {

assertEquals(“bob”,myObject.getName());

}

@Test

public void testInitialSize() {

The MyObject constructor will be called at least once for each @Test annotation in the class.
The MyObject constructor will be called a single time before testInitialName() is executed and not called before any of the other test methods.
The MyObject constructor will be called a single time before testInitialSize() is executed and not called before any of the other test methods.
The MyObject constructor will not be called and testInitialName will throw a null pointer exception.
The MyObject constructor will not be called and a @Before annotation is needed to provide a method to set the initial state of myObject.

Week 2: Engineering Maintainable Android Apps Coursera Quiz Answers

Quiz 2: Testing II Quiz

Q1. What is an Android Instrumentation Test (select all that apply)?

a performance test for an application to measure its memory usage.
a test that includes a code coverage calculation
a test that measures user interactions with the user interface
a performance test for an application to measure its CPU usage.
an integration test that includes the Android runtime libraries.

Q2. Which of the following are true of unit tests vs. integration tests (select all that apply)?

Integration tests isolate individual components while unit tests check the interactions of multiple components.
Unit tests are typically slower than integration tests.
The failure of a unit test often more directly points to the source of the failure than an integration test,
Unit tests isolate individual components while integration tests check the interactions of multiple components.
Integration tests are often slower than unit tests.

Q3. Which of the following creates a valid mock PostalCodeProvider that will return “37212” for the following call (select all that apply):

1 postalCodeProvider.getPostalCode(2.11, 3.09)

12345678910111213