1.3 What is the final keyword used for in Java? Describe its three main uses. [10 Marks]

1.2 Explain why Integer a = 100; Integer b = 100; returns true for a == b but Integer c = 200; Integer d = 200; returns false for c == d and suggest the correct way of comparing Integers.[5 Marks]

1.1 The concept of ‘Autoboxing’ is of paramount importance in Java Language. Explain what Autoboxing is and provide a scenario where it occurs[5 Marks]

2.5 For the below Java Code Snippets contain bugs or issues that you need to identify the problem in the code and state the exact problem.

Code Snippet 5

(10 MARKS)

2.4 For the below Java Code Snippets contain bugs or issues that you need to identify the problem in the code and state the exact problem.

Code Snippet 4

(5 MARKS)

2.3 For the below Java Code Snippets contain bugs or issues that you need to identify the problem in the code and state the exact problem.

Code Snippet 3

(5 MARKS)

2.2 For the below Java Code Snippets contain bugs or issues that you need to identify the problem in the code and state the exact problem.

Code Snippet 2

(5 MARKS)

2.1 For the below Java Code Snippets contain bugs or issues that you need to identify the problem in the code and state the exact problem.

Code Snippet 1

(5 MARKS)

3.2 The following Java program attempts to create two threads that print numbers from 1 to 5. However, the output is sometimes incorrect or inconsistent.

Possible Output

a. Explain why does the output sometimes show numbers printed in a mixed order (e.g., Thread-B: 3 before Thread-A: 3)

3.1 Design a class hierarchy to model different types of trade tariffs. Your implementation should demonstrate understanding of inheritance and polymorphism.

Class Design

·         Create an abstract base class Tariff with these properties:

·         rate (double - represents percentage rate)

·         effectiveDate (String)

·         and one abstract method: double calculateDuty(double productValue)

Create three concrete subclasses that extend Tariff:

·         SteelTariff (adds property: steelType String)

·         AluminumTariff (adds property: countryOfOrigin String)

·         ChinaTariff (adds property: productCategory String)

Method Implementation

·         Implement the calculateDuty() method differently for each subclass:

·         Base calculation is productValue * rate

·         Add 5% surcharge if steelType is "stainless"

·         For AluminumTariff:

·         Base calculation is productValue * rate

·         Add 10% surcharge if countryOfOrigin is "Canada"

For ChinaTariff:

·         Flat $500 fee if productCategory is "electronics"

·         Otherwise productValue * rate

Demonstration

Create a main method that:

·         Creates an array of Tariff objects containing one instance of each subclass

·         Initializes each with appropriate values.

·         Iterates through the array, calling calculateDuty() for a sample product value of $10,000

·         Prints the calculated duty for each tariff

(25 MARKS)