Android Programming using Java — DU B.Sc. (Hons) Computer Science Previous Year Question Papers

Using JAVA (DSE - I) Science/Physical Science/B.Sc. (Hons.) (Parts of a question must be answered together) 1. (a) What is the difference between match_parent and wrap _content attribute values in Android layout files ? 3 (b) What does the term "Package" mean in Java? How do packages help manage the namespace and scope of variables and methods? (c) What is a Bundle in Java, and how do you create and use it to pass data between two Activities in an Android application? Explain using Java code. 3 (d) Describe an abstract class in Java. How is it different from a Regular (Concrete) class ? Mention two key differences between them. (e) What are the advantages of using the Android Emulator in Android development ? What prerequisites must be enabled on a computer to use the android Emulator? 3 (f) What is the purpose of calling super on Create (saved Instance State ) in the on Create () method of an Android Activity? 3 (g) List and explain any three key architectural components of an Android application. Android using a diagram. 4 Consider a scenario where an Activity triggers an implicit intent to view a URL. (i) Write short notes on any two of the following : Activity Stack Dalvik Virtual Machine (Attempt and 4 questions) (Parts of a question must be answered together) 2. (a) An Android Activity contains two CheckBoxes. Write Java code to determine which CheckBox is selected by the user and display the corresponding value in a Toast message. (b) Explain the different types of constructors in Java. Write a Java class named "Robot" with a static variable to keep track of the robot population, and three instance variables: robot Name, robot Weight, and robot Height. Ensure the class properly initializes these variables and includes a public method to display the details of Robots. 3. (a) In Android, what is an Array Adapter and how is it used in creating a list of items in a Spinner ? Write Java code which uses an XML list from the resource folder. 7 (b) What is Polymorphism in Java? Explain the two types of polymorphism with examples. 4. (a) What is an On Click Listener in Android ? Describe three different ways to handle click events in an Android application. 7 (b) Explain the following code fragments: set Content View (R. layout. main); ii. findView Byld (R. id. Btn 1); ili. Log. d (TAG, "resource not available") iv. Intent in = new Intent (Current Activity. this, Next Activity. class); startActivity 5. (a) Define LayoutInflater in Android. Explain its role, common usage, and provide an example of how it is used to inflate a layout in an Android application. 7 (b) Define a Java class Student with three data members (studentld as Integer, name and course as String) implementing Serializable Interface. In MainActivity, initalize a Student object and pass it to DetailsActivity using 6. (a) Fill in the blanks : 7 i In Java, when a subclass provides a specific implementation of a method already defined in its superclass, this is called ...• ...•.•