Question

C#

Write a program that takes a list of information and grades of the students of a class and perform some processing. Take the following steps to write the program.

The program must give the user two options such as a menu. At the beginning of the program must ask the following from the user:

Which task you want to do (choose an option between 1-2),

1- Entering new information

2- Searching a student If the user types something rather than 1-2, the program must print invalid response.

After completing one task, the program must ask the user if you want to do another task. If the user types yes, it should go to the beginning of the menu and asks which task you want to do? The program must continue to perform the tasks and asking the user if you want to perform a task as long as the user types yes if the user types No at the end of a task, the program must stop and prints a message:

Thank you and have a good day!

You should write your code as per the following instructions:

 If the user types 1 for entering new information:

 The program must ask the user how many students you have. (save it in a variable named num)

 You need to build one dimensional arrays with the size of num for names, last names, and student ids

 The program must take the student names, last names and student id, each one must be saved in an array.

 Choose appropriate data type for each array.

 If the user types 2 :  It must ask the following from the user:

 Type the student ID of the student you want?

 The student ID typed by the user must be saved in a variable named sd.

 The program must find the student that his ID matches with what the user types (sd).

 Print the information of that student including name, last name and grade?

Answer 1

Create a C# console application with the name StudentInfoAndGrade, add the below code in Program.cs

Program.cs

using System;

namespace StudentInfoAndGrade
{
    class Program
    {
        static void Main(string[] args)
        {
            //variable declarations
            bool doAgain = true;
            int userChoice;
            int num = -1;
            string[] firstNames = new string[0];
            string[] lastNames = new string[0];
            string[] studentIDs = new string[0];
            double[] grades = new double[0];
            string sd;
            string repeat;
            //repeat the process until the user enters no
            while (doAgain)
            {
                //display the menu options
                Console.WriteLine("Which task you want to do (choose an option between 1-2):");
                Console.WriteLine("1- Entering new information");
                Console.WriteLine("2- Searching a student");
                //read the user choice
                Console.Write("Enter your choice: ");
                userChoice = Convert.ToInt32(Console.ReadLine());
                //display error message if choice is invalid
                if (userChoice < 1 || userChoice > 2)
                    Console.WriteLine("Invalid response.");
                else
                {
                    //if user enters 1
                    if (userChoice == 1)
                    {
                        //prompt and read the number of students
                        Console.Write("\nHow many students you have? ");
                        num = Convert.ToInt32(Console.ReadLine());
                        //initialize the size of the arrays
                        firstNames = new string[num];
                        lastNames = new string[num];
                        studentIDs = new string[num];
                        grades = new double[num];
                        //run a loop to read the student information
                        for (int i = 0; i < num; i++)
                        {
                            Console.WriteLine("\nEnter details of student #" + (i + 1));
                            Console.Write("Enter firstname: ");
                            firstNames[i] = Console.ReadLine();
                            Console.Write("Enter lastname: ");
                            lastNames[i] = Console.ReadLine();
                            Console.Write("Enter ID: ");
                            studentIDs[i] = Console.ReadLine();
                            Console.Write("Enter grade: ");
                            grades[i] = Convert.ToDouble(Console.ReadLine());
                        }
                        Console.WriteLine();
                    }
                    //if the user enter 2
                    else
                    {
                        //num will be -1, if there are no student information entered
                        if (num == -1)
                        {
                            Console.WriteLine("Enter student information before search.");
                        }
                        else
                        {
                            //prompt and read the ID of the student to search
                            Console.Write("\nType the student ID of the student you want? ");
                            sd = Console.ReadLine();
                            int index = -1;
                            //run a loop and search the ID
                            for (int i = 0; i < num; i++)
                            {
                                if (studentIDs[i].ToLower() == sd.ToLower())
                                    index = i;
                            }
                            //if the index is -1 print student not found
                            if (index == -1)
                                Console.WriteLine("Student not found with the given ID.");
                            else
                            {
                                //display the student information if the ID is found
                                Console.WriteLine("\nFirst Name: " + firstNames[index]);
                                Console.WriteLine("Last Name: " + lastNames[index]);
                                Console.WriteLine("Grade: " + grades[index].ToString());
                            }
                        }
                    }
                    //prompt and read if the user wishes to perform another task
                    Console.Write("Do you want to do another task(yes/no)? ");
                    repeat = Console.ReadLine();
                    //continue if yes is entered
                    if (repeat.ToLower() == "yes")
                        doAgain = true;
                    //else terminate the loop
                    else
                    {
                        doAgain = false;
                        Console.WriteLine("\nThank you and have a good day!");
                    }
                }
            }
            Console.ReadKey();
        }
    }
}

Output:

Program Screenshot:

Let me know if you have any concerns with the above solution.