OOPS LAB : EX NO 11: EXCEPTION HANDLING

                                            USER DEFINED EXCEPTIONS

Case Study 1: Online Banking System  (R NO :1 - 5)

Scenario:

A bank application must prevent invalid withdrawals.

Step-by-step Questions:

1. Define a class InsufficientBalanceException derived from exception.
2. Create a BankAccount class with balance as a private member.
3. Write a method withdraw(amount) that:
• Throws exception if amount > balance.
4. Display a meaningful error message using what().
5. Write a main() function to:
• Accept withdrawal amount from user
• Handle exception using try-catch
6. Extend:
• Add another exception for minimum balance violation.

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Case Study 2: Student Result Processing System    (R NO :6 - 10)

Scenario:

Marks entered should be within valid range.

Step-by-step Questions:

1. Create a user-defined exception class InvalidMarksException.
2. Accept marks for 5 subjects.
3. Throw exception if:
• Marks < 0 or > 100
4. Handle exception and prompt user to re-enter marks.
5. Calculate average only if all inputs are valid.
6. Extend:
• Add exception for "Fail if any subject < 40".

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Case Study 3: E-Commerce Order System   (R NO :11 - 15)

Scenario:

Order quantity must be valid.

Step-by-step Questions:

1. Create exception class InvalidQuantityException.
2. Create a class Product with:
• product name, stock
3. Write function placeOrder(quantity):
• Throw exception if quantity <= 0 or exceeds stock
4. Catch exception and display error.
5. Update stock if order is successful.
6. Extend:
• Add exception for "OutOfStockException".

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Case Study 4: Employee Salary System  (R NO :16 - 20)

Scenario:

Salary constraints must be validated.

Step-by-step Questions:

1. Define InvalidSalaryException.
2. Create Employee class with salary.
3. Throw exception if:
• Salary < minimum wage
4. Handle exception in main().
5. Display proper message.
6. Extend:
• Add exception for bonus exceeding salary.

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Case Study 5: File Upload System   (R NO :21 - 25)

Scenario: 

File size limit must not exceed.

Step-by-step Questions:

1. Create FileSizeTooLargeException.
2. Accept file size and file type as input (in MB) (e.g., JPG, PNG, PDF)
3. Throw exception if size > allowed limit (e.g., 10MB). and type not matched also 
4. Handle exception  for file size extended and unsupported file type.and display message.

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Case Study 6: ATM PIN Verification   (R NO :26 - 30)

Scenario:

User gets limited attempts.

Step-by-step Questions:

1. Create InvalidPINException.
2. Allow only 3 attempts to enter correct PIN.
3. Throw exception after 3 failed attempts.
4. Handle exception and block access.
5. Extend:
• Add exception for "CardBlockedException".

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Case Study 7: Online Ticket Booking   (R NO :31 - 40)

Scenario:

Seats must be available.

Step-by-step Questions:

1. Create SeatUnavailableException.
2. Store total seats and booked seats.
3. Throw exception if booking exceeds available seats.
4. Handle exception gracefully.
5. Extend:
• Add waiting list logic.

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Case Study 8: Library Management System   (R NO :41 - 50)

Scenario:

Book issuing rules.

Step-by-step Questions:

1. Create BookNotAvailableException.
2. Create class Library with book stock.
3. Throw exception if book count = 0.
4. Handle exception in main.
5. Extend:
• Add fine exception for late return.

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Case Study 9: Login Authentication System   (R NO :51 - 55)

Scenario:

Invalid login attempts.

Step-by-step Questions:

1. Create InvalidLoginException.
2. Accept username and password.
3. Throw exception if credentials mismatch.
4. Handle exception and show error.
5. Extend:
• Lock account after multiple failures.

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Case Study 10: Electricity Billing System   (R NO :56 - 61)

Scenario:

Invalid meter reading.

Step-by-step Questions:

1. Create InvalidReadingException.
2. Accept previous and current readings.
3. Throw exception if:
• Current < previous
4. Handle exception and ask for re-entry.
5. Extend:
• Add exception for abnormal consumption.