Proposed exercise
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
Output
Solution
using System;
public class CitiesDatabase
{
struct city
{
public string name;
public uint inhabitants;
}
public static void Main()
{
int maxCities= 500;
city[] cities = new city[maxCities];
int amount = 0;
int currentCityNumber;
string option;
string textToSearch;
bool found;
string textToModify;
bool finished = false;
do
{
Console.WriteLine();
Console.WriteLine("Cities database");
Console.WriteLine();
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.WriteLine();
Console.Write("Choose an option: ");
option = Console.ReadLine();
switch (option)
{
case "0":
finished = true;
break;
case "1":
if (amount > maxCities- 1)
Console.WriteLine("the database is full");
else
{
Console.WriteLine("Entering data for city number {0}", amount + 1);
Console.Write("Enter the city name: ");
cities[amount].name = Console.ReadLine();
Console.Write("Enter the inhabitants numbers: ");
cities[amount].inhabitants = Convert.ToUInt32(Console.ReadLine());
Console.WriteLine("The data was entered correctly");
amount++;
}
break;
case "2":
for (int i = 0; i < amount; i++)
{
Console.WriteLine("{0}: {1}, {2} inhabitants",
i + 1, cities[i].name, cities[i].inhabitants);
}
Console.WriteLine();
break;
case "3":
Console.Write("Enter the city number: ");
currentCityNumber = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Enter a new data for a city number: {0}",
currentCityNumber);
Console.Write("City name (was {0}; hit ENTER to leave as is): ",
cities[currentCityNumber - 1].name);
textToModify = Console.ReadLine();
if (textToModify != "")
cities[currentCityNumber - 1].name = textToModify;
Console.Write("Inhabitants (was {0}; hit ENTER to leave as is): ",
cities[currentCityNumber - 1].inhabitants);
textToModify = Console.ReadLine();
if (textToModify != "")
cities[currentCityNumber - 1].inhabitants = Convert.ToUInt32(textToModify);
Console.WriteLine();
break;
case "4":
if (amount > maxCities- 1)
Console.WriteLine("The database is full");
else
{
Console.Write("Enter the number of the city to modify: ");
currentCityNumber = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Insert a new data at {0} position: ",
currentCityNumber);
amount++;
for (int i = (int)amount; i > currentCityNumber - 1; i--)
{
cities[i] = cities[i - 1];
}
Console.Write("City name: ");
cities[currentCityNumber - 1].name = Console.ReadLine();
Console.Write("Inhabitants: ");
cities[currentCityNumber - 1].inhabitants = Convert.ToUInt32(Console.ReadLine());
}
break;
case "5":
Console.Write("Enter the city number for delete: ");
currentCityNumber = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Deleting the number {0}", currentCityNumber);
for (int i = currentCityNumber - 1; i < amount; i++)
{
cities[i] = cities[i + 1];
}
amount--;
break;
case "6":
Console.Write("Enter the text to search: ");
textToSearch = Console.ReadLine();
found = false;
for (int i = 0; i < amount; i++)
{
if (cities[i].name.ToUpper().IndexOf(textToSearch.ToUpper()) >= 0)
{
Console.WriteLine("{0} found in {1}",
textToSearch, cities[i].name);
found = true;
}
}
if (!found)
Console.WriteLine("Not found.");
break;
case "7":
for(int i = 0;i < amount;i++) {
// First, the whole name to lower case
string lowerCaseName = cities[i].name.ToLower();
// then, first letter to uppercase
string correctedName = lowerCaseName.Substring(0, 1).ToUpper()
+ lowerCaseName.Substring(1);
// and then the letters after a space
for (int j = 1; j < correctedName.Length - 2; j++)
{
if (correctedName[j] == ' ')
correctedName = correctedName.Substring(0, j) + " " +
correctedName.Substring(j + 1, 1).ToUpper() +
correctedName.Substring(j + 2);
}
cities[i].name = correctedName;
}
break;
default:
Console.WriteLine("Wrong option ");
break;
}
} while (!finished);
}
}