Scenario:
You are required to design a class to
hold details of a metro station, including the number of tickets sold. The station should have the following
properties:
|
Property
Name |
Examples |
Validation |
Public
Accessors |
|
Name |
“Aldgate” “Barbican” |
Not “” |
Get Set |
|
Line |
“District” “Central” |
Not “” |
Get Set |
|
TicketsSold |
1234 |
0 to 999999 |
Get |
Examples of names and lines can be found
at https://en.wikipedia.org/wiki/List_of_London_Underground_stations .
The Station class should have a public method sellTicket() which adds 1 to the TicketsSold property.
Task 1:
Draw a class diagram showing the Station
class – you might want to use draw.io to produce the diagram, paste your
diagram into the box below:
Task 2: Implement your Station class in c# and paste the source code below:
using System;
using MetroStation;
namespace MetroStation
{
// Here we are Defining Station class
which include properties,
// Name, Line and TicketsSold.
class Station
{
private string
station_name = "" ;
private string
station_line = "";
private int
TicketSold = 0; // Ticket Sold counter.
// Property
to get or set the station_name.
public string Name
{
get
{
return
station_name;
}
set
{ // Checking if the provided value is null
or empty.
if (string.IsNullOrEmpty(value))
{
// If it’s, throw ArgumentException with
Specific Message and
// parameter name.
throw new
ArgumentException("Station Name cannot be Blank!!!","Name");
}
station_name = value;
}
}
//
Property to get or set station_line.
public string Line
{
get
{
return
station_line;
}
set
{ // Checking if the provided value is
null or empty.
if (string.IsNullOrEmpty(value))
{
// If it’s, throw ArgumentException with Specific Message
//
parameter name.
throw new
ArgumentException("Station Line cannot be Blank!!!", "Line");
}
station_line = value;
}
}
//
Property to get number of tickets sold.
public int
TicketsSold
{
get
{
return
TicketSold;
}
}
//
Method for approximating the sale of ticket.
public void
SellTicket()
{
//
Keeps track of number of tickets sold
TicketSold++;
}
}
}
Task 3 (Advanced)
Add a property ‘ID’ to your station
class, which can be get and set. The ID
property takes the form of a number in the range 1000 to 2000.
Add the following code to your Station
class:
...
private
String _id;
public
string ID // property
{
get {
return
_id;
}
set {
if (value == ""){
throw
new ArgumentException("ID cannot be blank!","ID");
}
_id = value;
}
}
...
The following code can be used in a
console application to test your Station class:
//Test
for blank
try
{
myStation.ID = "";
}
catch
(Exception ex)
{
Console.WriteLine(ex.Message);
}
Modify the
set() method of Station.ID to throw an error if the ID is not a number or is
out of the 1000 ro 2000 range.
// So here we are Introducing new property id in Station Class
...
private string id= “”;
public string ID
{
get
{
return id;
}
set
{
// So here we are
checking if the number is numeric or not,
// If the value
(Station ID) falls between 1000 and 2000 or not,
if
(!IsNumericString(value) || int.Parse(value) <= 1000 || int.Parse(value) >= 2000)
{
throw new ArgumentException("Station ID should be Numeric value but also between
1000 and
2000.", "ID");
}
id = value;
}
}
// IsNumericString method for checking if a value is numeric or
not
// Got an idea on, how to use IsNumeric method from
// Identify if a string is numeric in C# | Techie Delight
private static bool IsNumericString(string value)
{
return int.TryParse(value, out _);
}
. . .
Paste your main method (console) here:
class Program
{
static void Main(string[]
args)
{
//
Create an instance of the Station class
Station
station = new ();
try
{
// Set
properties
// Here
we check for the ID if it is numeric or not
station.ID = "ABC";
station.Name = "Preston";
station.Line = "District";
station.SellTicket();
Console.WriteLine(" Here are your ticket Details
");
Console.WriteLine("Station Id: " +
station.ID);
Console.WriteLine("Station Name: " +
station.Name);
Console.WriteLine("Station Line: " +
station.Line);
Console.WriteLine("Tickets Sold: " +
station.TicketsSold);
}
catch
(Exception ex)
{
Console.WriteLine(ex.Message);
}
// Just for a gap
Console.WriteLine("");
try
{ // Here we are checking if the provided id
is within the range or not.
station.ID = "2999";
station.Name = "London";
station.Line = "Central";
station.SellTicket();
Console.WriteLine(" Here are your ticket Details
");
Console.WriteLine("Station Id: " +
station.ID);
Console.WriteLine("Station Name: " +
station.Name);
Console.WriteLine("Station Line: " +
station.Line);
Console.WriteLine("Tickets Sold: " +
station.TicketsSold);
}
catch
(Exception ex)
{
Console.WriteLine(ex.Message);
}
// Just for a gap
Console.WriteLine("");
try
{ // Thus, this will show the valid output,
// if everything
is provided correctly.
station.ID
= "1222" ;
station.Name = "Edinburgh";
station.Line = "West";
station.SellTicket();
Console.WriteLine(" Here are your ticket Details
");
Console.WriteLine("Station Id: " +
station.ID);
Console.WriteLine("Station Name: " +
station.Name);
Console.WriteLine("Station Line: " +
station.Line);
Console.WriteLine("Tickets Sold: " +
station.TicketsSold);
}
catch
(Exception ex)
{
Console.WriteLine(ex.Message);
}
}
}
Paste the output from your console app here:
Station
ID should be Numeric value but also between 1000 and 2000. (Parameter 'ID')
Station
ID should be Numeric value but also between 1000 and 2000. (Parameter 'ID')
Here are your ticket Details
Station
Id: 1222
Station
Name: Edinburgh
Station
Line: West
Tickets
Sold: 1
C:\Users\40612246\OneDrive
- Edinburgh Napier University\Coursework1 OOP\Coursework1
OOP\bin\Debug\net6.0\Coursework1 OOP.exe (process 23852) exited with code 0.
To
automatically close the console when debugging stops, enable
Tools->Options->Debugging->Automatically close the console when
debugging stops.
Press
any key to close this window . . .
Comments
Post a Comment