Programming & Computer Science Answers

Dwayne runs a money lending business in which he offers different types of loans, such as personal loan, car loan on high rate of interest to those individuals who cannot get a loan from the commercial banks. As part of his business activities, Dwayne maintains a customer details register that contains the following information:
1:The contact details of all those persons to whom Dwayne has lent money.
2:The amount of money lent to each person.
3:The interest rate charged from each person.
Over the years, Dwayne's business has grown tremendously. This has caused an exponential increase in the number of customer details that he needs to maintain. As Dwayne uses a physicalregister to maintain the customer details, he faces the following problems:
1:In case the contact details of a customer changes, Dwayne needs to delete the previous entry and add a new entry for the respective customer.
2:The numbers of errors committed during the data entry process are high.
To address the preceding issues, Dwayne decides to computerize the task of maintaining the customer details. Therefore, he hires Elina, a freelance software developer, for the task. Elina conducts a meeting with Dwayne and notes the following requirements:
1:Dwayne does not have the budget to implement RDBMS. However, he wants that data is available all the time. As a result, the application must store the customer details persistently on Dwayne's computer.
2:The application should allow Dwayne to create and modify the customer details as per his requirements.
3:The application needs to store the customer details in such a way that the details can be read by only the application. Therefore, if the customer details file is opened by anyone other than the application, the content should not be readable as plain text.
Question:
Elina decides to develop the application using C#. Analyze the preceding scenario and answer the following questions:
1:Which classes of the .NET Framework should Elina use to implement file input and output operations in the application? Justify the reason for the same.
2:Describe the different methods of the classes that Elina would be using to implement file input and output operations in the application.

Elina develops the customer details maintenance application and the EMI calculator application and provides both the applications to Dwayne for testing. While testing the applications, Dwayne discovers the following problems:

1.The application displayed a message to the user to enter the path of the customer details file. However, the customer details maintenance application crashed as Dwayne mistakenly entered the wrong file path. Therefore, he asks Elina to modify the application so that it does not crash due to similar errors. Modify the code that Elina needs to accomplish the preceding task.
2.The EMI calculator application crashed when Dwayne accidentally entered zero as the rate of interest. Therefore, he asks Elina to modify the application so that it displays an error message if the principal amount, rate of interest, or tenure of the loan entered is invalid. Add the code snippet that Elina should use to modify the application according to the preceding requirements.

Elina has started developing the application. She needs to ensure that the application meets the following requirements:

1:When the application executes for the first time, it should perform the following tasks:
.Display a message to the user to specify the path of the file in which the customer details are to be stored.
.Create the customer details file at the user-defined location.
.Create a configuration file and store the path of the customer details file in the configuration file.
This configuration file needs to be used by the application to retrieve the location of the customer details file.

2:The user should be able to save data to the customer details file. Write the code that Elina should use to save data to the customer details file.
3:The user should be able to view the data stored in the customer details file. Write the code that Elina should use to read the data stored in the customer details file and display it to the user.

The development team of SoftSols Inc. analyzes the source code of the existing software and
notes the following observations:
The software contains a private class, named bookTickets, that contains the methods used to
perform ticket bookings for various flights.
There is no class or function that can be used to check the maintenance details of FlyHigh's
aircrafts.
Based on the preceding observations, the development team decides to perform the following
tasks:
Reuse the functions of the bookTickets class in a new class, named bookETicket, to add the
feature of e-ticket booking.
Create a new class named viewMaintenance that allows the maintenance personnel of FlyHigh
Airlines to view the maintenance details of aircrafts.
Write the code snippet that the development team should use to accomplish each of the preceding
tasks

Assembly Language program attributes for loading program using INT21 Services.

Which instruction makes trap flag zero? If there is no such instruction then how this task is performed?

What are the values required for following registers to write a character on serial port using INT 21?
AH = ………..
AL = ………..
DX = ………..