Practical Questions: Core Java Laboratory

For each of the following practical exercises, you are required to design, implement, and test a Java program. Ensure your code is well-structured, commented, and adheres to good programming practices.

1.     Write a Java program that displays the classic "Hello World!" message on the console.

o    Objective: To familiarize yourself with the basic structure of a Java program, compilation, and execution.

2.     Develop a Java program to generate and display various star (*) patterns on the console.

o    Objective: To practice using control flow statements (loops) and nested loops to create patterned output. Examples could include a right triangle, square, or pyramid.

3.     Create a Java program to calculate and display the area and perimeter of a circle.

o    Objective: To implement basic arithmetic operations, use appropriate data types for floating-point numbers, and take user input for the circle’s radius.

4.     Write a Java program that takes two binary numbers (as strings or suitable data types) as input from the user and calculates their sum, displaying the result in binary format.

o    Objective: To work with string manipulation or custom logic for binary arithmetic, demonstrating control flow and data conversion.

5.     Implement a Java program to reverse a given string.

o    Objective: To manipulate strings using loops, character access, or StringBuilder/StringBuffer classes, demonstrating string handling techniques.

6.     Develop a Java program that accepts a string input from the user and counts the occurrences of letters, spaces, numbers (digits), and any other special characters within that string.

o    Objective: To utilize string iteration and character classification methods (e.g., Character.isLetter(), Character.isDigit(), Character.isSpaceChar()).

7.     Write a Java function (method) that takes a character array representing a numeric value as input and calculates the sum of its individual digits.

o    Example: For char[] {‘1’, ‘2’, ‘3’}, the sum should be 6.

o    Objective: To demonstrate iteration over character arrays, type conversion from char to int, and basic arithmetic operations.

8.     Create a Java program to find and display the smallest and largest elements present in an array of integers.

o    Objective: To practice array traversal, comparison operators, and conditional logic to identify extreme values within a data structure.

9.     Design and implement a Java class (e.g., Car or Book) that demonstrates the effective use of constructors. Your class should include:

o    At least one default constructor and one parameterized constructor.

o    Instance variables that are initialized by these constructors.

o    A method to display the object’s state.

o    Objective: To understand object creation, initialization through constructors, and the basic lifecycle of objects in Java (acknowledging Java’s automatic garbage collection instead of explicit destructors).

10.                        Implement a Java program that demonstrates single-level inheritance.

o    Task: Create a Vehicle class (superclass) with common attributes (e.g., brand, year) and a Car class (subclass) that extends Vehicle, adding its own specific attributes (e.g., model, numberOfDoors). Show how to access superclass members and potentially override a method.

o    Objective: To apply the fundamental concepts of inheritance, super keyword, and method overriding.

11.                        Project: Develop a small console-based Java application that integrates concepts from Units 1-4 of the Core Java syllabus.

o    Objective: To apply your accumulated knowledge to solve a slightly more complex problem, demonstrating understanding of OOP principles, class design, data handling, and potentially user interaction and basic error handling. You may choose a topic like a simple "Student Management System," "Basic Inventory System," or a text-based "Quiz Application."

o    Submission: Your project should include source code files, a brief design document (UML/pseudocode), and instructions on how to compile and run the application.