How to: Perform String Manipulations by Using Basic String Operations
The following example uses some of the methods discussed in the Basic String Operations topics to construct a class that performs string manipulations in a manner that might be found in a real-world application. The MailToData class stores the name and address of an individual in separate properties and provides a way to combine the City, State, and Zip fields into a single string for display to the user. Furthermore, the class allows the user to enter the city, state, and ZIP Code information as a single string; the application automatically parses the single string and enters the proper information into the corresponding property.
For simplicity, this example uses a console application with a command-line interface.
Example
Class MainClass
Public Shared Sub Main()
Dim MyData As New MailToData()
Console.Write("Enter Your Name: ")
MyData.Name = Console.ReadLine()
Console.Write("Enter Your Address: ")
MyData.Address = Console.ReadLine()
Console.Write("Enter Your City, State, and ZIP Code separated by spaces: ")
MyData.CityStateZip = Console.ReadLine()
Console.WriteLine()
If MyData.Validated Then
Console.WriteLine("Name: {0}", MyData.Name)
Console.WriteLine("Address: {0}", MyData.Address)
Console.WriteLine("City: {0}", MyData.City)
Console.WriteLine("State: {0}", MyData.State)
Console.WriteLine("ZIP Code: {0}", MyData.Zip)
Console.WriteLine("The following address will be used:")
Console.WriteLine(MyData.Address)
Console.WriteLine(MyData.CityStateZip)
End If
End Sub
End Class
Public Class MailToData
Private strName As String = ""
Private strAddress As String = ""
Private strCityStateZip As String = ""
Private strCity As String = ""
Private strState As String = ""
Private strZip As String = ""
Private parseSucceeded As Boolean = False
Public Property Name() As String
Get
Return strName
End Get
Set
strName = value
End Set
End Property
Public Property Address() As String
Get
Return strAddress
End Get
Set
strAddress = value
End Set
End Property
Public Property CityStateZip() As String
Get
Return String.Format("{0}, {1} {2}", strCity, strState, strZip)
End Get
Set
strCityStateZip = value.Trim()
ParseCityStateZip()
End Set
End Property
Public Property City() As String
Get
Return strCity
End Get
Set
strCity = value
End Set
End Property
Public Property State() As String
Get
Return strState
End Get
Set
strState = value
End Set
End Property
Public Property Zip() As String
Get
Return strZip
End Get
Set
strZip = value
End Set
End Property
Public ReadOnly Property Validated As Boolean
Get
Return parseSucceeded
End Get
End Property
Private Sub ParseCityStateZip()
Dim msg As String = Nothing
Const msgEnd As String = vbCrLf +
"You must enter spaces between city, state, and zip code." +
vbCrLf
' Throw a FormatException if the user did not enter the necessary spaces
' between elements.
Try
' City may consist of multiple words, so we'll have to parse the
' string from right to left starting with the zip code.
Dim zipIndex As Integer = strCityStateZip.LastIndexOf(" ")
If zipIndex = -1 Then
msg = vbCrLf + "Cannot identify a zip code." + msgEnd
Throw New FormatException(msg)
End If
strZip = strCityStateZip.Substring(zipIndex + 1)
Dim stateIndex As Integer = strCityStateZip.LastIndexOf(" ", zipIndex - 1)
If stateIndex = -1 Then
msg = vbCrLf + "Cannot identify a state." + msgEnd
Throw New FormatException(msg)
End If
strState = strCityStateZip.Substring(stateIndex + 1, zipIndex - stateIndex - 1)
strState = strState.ToUpper()
strCity = strCityStateZip.Substring(0, stateIndex)
If strCity.Length = 0 Then
msg = vbCrLf + "Cannot identify a city." + msgEnd
Throw New FormatException(msg)
End If
parseSucceeded = True
Catch ex As FormatException
Console.WriteLine(ex.Message)
End Try
End Sub
End Class
using System;
class MainClass
{
static void Main()
{
MailToData MyData = new MailToData();
Console.Write("Enter Your Name: ");
MyData.Name = Console.ReadLine();
Console.Write("Enter Your Address: ");
MyData.Address = Console.ReadLine();
Console.Write("Enter Your City, State, and ZIP Code separated by spaces: ");
MyData.CityStateZip = Console.ReadLine();
Console.WriteLine();
if (MyData.Validated) {
Console.WriteLine("Name: {0}", MyData.Name);
Console.WriteLine("Address: {0}", MyData.Address);
Console.WriteLine("City: {0}", MyData.City);
Console.WriteLine("State: {0}", MyData.State);
Console.WriteLine("Zip: {0}", MyData.Zip);
Console.WriteLine("\nThe following address will be used:");
Console.WriteLine(MyData.Address);
Console.WriteLine(MyData.CityStateZip);
}
}
}
public class MailToData
{
string name = "";
string address = "";
string citystatezip = "";
string city = "";
string state = "";
string zip = "";
bool parseSucceeded = false;
public string Name
{
get{return name;}
set{name = value;}
}
public string Address
{
get{return address;}
set{address = value;}
}
public string CityStateZip
{
get {
return String.Format("{0}, {1} {2}", city, state, zip);
}
set {
citystatezip = value.Trim();
ParseCityStateZip();
}
}
public string City
{
get{return city;}
set{city = value;}
}
public string State
{
get{return state;}
set{state = value;}
}
public string Zip
{
get{return zip;}
set{zip = value;}
}
public bool Validated
{
get { return parseSucceeded; }
}
private void ParseCityStateZip()
{
string msg = "";
const string msgEnd = "\nYou must enter spaces between city, state, and zip code.\n";
// Throw a FormatException if the user did not enter the necessary spaces
// between elements.
try
{
// City may consist of multiple words, so we'll have to parse the
// string from right to left starting with the zip code.
int zipIndex = citystatezip.LastIndexOf(" ");
if (zipIndex == -1) {
msg = "\nCannot identify a zip code." + msgEnd;
throw new FormatException(msg);
}
zip = citystatezip.Substring(zipIndex + 1);
int stateIndex = citystatezip.LastIndexOf(" ", zipIndex - 1);
if (stateIndex == -1) {
msg = "\nCannot identify a state." + msgEnd;
throw new FormatException(msg);
}
state = citystatezip.Substring(stateIndex + 1, zipIndex - stateIndex - 1);
state = state.ToUpper();
city = citystatezip.Substring(0, stateIndex);
if (city.Length == 0) {
msg = "\nCannot identify a city." + msgEnd;
throw new FormatException(msg);
}
parseSucceeded = true;
}
catch (FormatException ex)
{
Console.WriteLine(ex.Message);
}
}
private string ReturnCityStateZip()
{
// Make state uppercase.
state = state.ToUpper();
// Put the value of city, state, and zip together in the proper manner.
string MyCityStateZip = String.Concat(city, ", ", state, " ", zip);
return MyCityStateZip;
}
}
When the preceding code is executed, the user is asked to enter his or her name and address. The application places the information in the appropriate properties and displays the information back to the user, creating a single string that displays the city, state, and ZIP Code information.