Exercise
Cities database
Objetive
Create a database to store information about cities.
In a first approach, we will store only the name of each city and the number of inhabitants, and allocate space for up to 500 cities.
The menu should include the following options:
1 .- Add a new city (at the end of the existing data)
2 .- View all cities (name and inhabitants)
3 .- Modify a record (rename and / or change number of inhabitants)
4 .- Insert a new record (in a specified position, moving the following ones to the right)
5 .- Delete a record (moving the following ones to the left so that no empty spaces are left)
6 .- Search in the records (display the ones which contain a certain text in their name, whether in upper or lower case, using partial search)
7 .- Correct the capitalization of the names (turn into uppercase the first letter and the ones after a space, and make the rest lowercase).
0 .- Exit
Example Code
using System; // Import the System namespace for basic functionality
using System.Linq; // Import LINQ to use string manipulation and search functionality
class Program // Define the main class
{
// Define the structure for a city
struct City
{
public string Name; // Name of the city
public int Inhabitants; // Number of inhabitants
}
static void Main() // The entry point of the program
{
City[] cities = new City[500]; // Array to store up to 500 cities
int currentCityCount = 0; // Counter to keep track of the current number of cities
while (true) // Infinite loop to display the menu repeatedly
{
// Display the menu options
Console.WriteLine("1. Add a new city");
Console.WriteLine("2. View all cities");
Console.WriteLine("3. Modify a record");
Console.WriteLine("4. Insert a new record");
Console.WriteLine("5. Delete a record");
Console.WriteLine("6. Search in the records");
Console.WriteLine("7. Correct the capitalization of the names");
Console.WriteLine("0. Exit");
Console.Write("Select an option: ");
string choice = Console.ReadLine(); // Read the user's choice
// Perform actions based on the user's choice
switch (choice)
{
case "1": // Add a new city
if (currentCityCount < 500) // Check if there is space for more cities
{
Console.Write("Enter the city name: ");
string name = Console.ReadLine();
Console.Write("Enter the number of inhabitants: ");
int inhabitants = int.Parse(Console.ReadLine());
cities[currentCityCount] = new City { Name = name, Inhabitants = inhabitants }; // Add the city to the array
currentCityCount++;
Console.WriteLine("City added successfully!");
}
else
{
Console.WriteLine("Database is full!");
}
break;
case "2": // View all cities
Console.WriteLine("Cities:");
for (int i = 0; i < currentCityCount; i++)
{
Console.WriteLine($"{cities[i].Name} - {cities[i].Inhabitants} inhabitants");
}
break;
case "3": // Modify a record
Console.Write("Enter the name of the city to modify: ");
string cityToModify = Console.ReadLine();
bool found = false;
for (int i = 0; i < currentCityCount; i++)
{
if (cities[i].Name.Equals(cityToModify, StringComparison.OrdinalIgnoreCase))
{
found = true;
Console.Write("Enter the new name: ");
cities[i].Name = Console.ReadLine();
Console.Write("Enter the new number of inhabitants: ");
cities[i].Inhabitants = int.Parse(Console.ReadLine());
Console.WriteLine("City updated successfully!");
break;
}
}
if (!found) Console.WriteLine("City not found!");
break;
case "4": // Insert a new record
Console.Write("Enter the position to insert at (1 to {0}): ", currentCityCount + 1);
int position = int.Parse(Console.ReadLine()) - 1;
if (position >= 0 && position <= currentCityCount)
{
Console.Write("Enter the city name: ");
string cityName = Console.ReadLine();
Console.Write("Enter the number of inhabitants: ");
int cityInhabitants = int.Parse(Console.ReadLine());
for (int i = currentCityCount; i > position; i--)
{
cities[i] = cities[i - 1]; // Move cities to the right
}
cities[position] = new City { Name = cityName, Inhabitants = cityInhabitants };
currentCityCount++;
Console.WriteLine("City inserted successfully!");
}
else
{
Console.WriteLine("Invalid position!");
}
break;
case "5": // Delete a record
Console.Write("Enter the name of the city to delete: ");
string cityToDelete = Console.ReadLine();
found = false;
for (int i = 0; i < currentCityCount; i++)
{
if (cities[i].Name.Equals(cityToDelete, StringComparison.OrdinalIgnoreCase))
{
found = true;
for (int j = i; j < currentCityCount - 1; j++)
{
cities[j] = cities[j + 1]; // Shift cities to the left
}
currentCityCount--;
Console.WriteLine("City deleted successfully!");
break;
}
}
if (!found) Console.WriteLine("City not found!");
break;
case "6": // Search in the records
Console.Write("Enter the text to search for: ");
string searchText = Console.ReadLine().ToLower(); // Make the search case-insensitive
Console.WriteLine("Search results:");
bool foundSearch = false;
for (int i = 0; i < currentCityCount; i++)
{
if (cities[i].Name.ToLower().Contains(searchText)) // Partial search
{
Console.WriteLine($"{cities[i].Name} - {cities[i].Inhabitants} inhabitants");
foundSearch = true;
}
}
if (!foundSearch) Console.WriteLine("No cities found matching the search criteria.");
break;
case "7": // Correct the capitalization of the names
for (int i = 0; i < currentCityCount; i++)
{
cities[i].Name = System.Globalization.CultureInfo.CurrentCulture.TextInfo.ToTitleCase(cities[i].Name.ToLower());
}
Console.WriteLine("Capitalization corrected for all city names.");
break;
case "0": // Exit the program
Console.WriteLine("Exiting program...");
return;
default:
Console.WriteLine("Invalid option! Please try again.");
break;
}
Console.WriteLine("Press any key to continue...");
Console.ReadKey(); // Wait for user input before continuing
}
}
}