How to: Write Characters to a String
The following code example writes a certain number of characters from a character array into an existing string, starting at a specified place in the array. Use StringWriter to do this, as demonstrated below.
Example
Imports System
Imports System.IO
Imports System.Text
Public Class CharsToStr
Public Shared Sub Main()
' Create an instance of StringBuilder that can then be modified.
Dim sb As New StringBuilder("Some number of characters")
' Define and create an instance of a character array from which
' characters will be read into the StringBuilder.
Dim b() As Char = {" ","t","o"," ","w","r","i","t","e"," ","t","o","."}
' Create an instance of StringWriter
' and attach it to the StringBuilder.
Dim sw As New StringWriter(sb)
' Write three characters from the array into the StringBuilder.
sw.Write(b, 0, 3)
' Display the output.
Console.WriteLine(sb)
' Close the StringWriter.
sw.Close()
End Sub
End Class
using System;
using System.IO;
using System.Text;
public class CharsToStr
{
public static void Main()
{
// Create an instance of StringBuilder that can then be modified.
StringBuilder sb = new StringBuilder("Some number of characters");
// Define and create an instance of a character array from which
// characters will be read into the StringBuilder.
char[] b = {' ','t','o',' ','w','r','i','t','e',' ','t','o','.'};
// Create an instance of StringWriter
// and attach it to the StringBuilder.
StringWriter sw = new StringWriter(sb);
// Write three characters from the array into the StringBuilder.
sw.Write(b, 0, 3);
// Display the output.
Console.WriteLine(sb);
// Close the StringWriter.
sw.Close();
}
}
using namespace System;
using namespace System::IO;
using namespace System::Text;
public ref class CharsToStr
{
public:
static void Main()
{
// Create an instance of StringBuilder that can then be modified.
StringBuilder^ sb = gcnew StringBuilder("Some number of characters");
// Define and create an instance of a character array from which
// characters will be read into the StringBuilder.
array<Char>^ b = {' ','t','o',' ','w','r','i','t','e',' ','t','o','.'};
// Create an instance of StringWriter
// and attach it to the StringBuilder.
StringWriter^ sw = gcnew StringWriter(sb);
// Write three characters from the array into the StringBuilder.
sw->Write(b, 0, 3);
// Display the output.
Console::WriteLine(sb);
// Close the StringWriter.
sw->Close();
}
};
int main()
{
CharsToStr::Main();
}
Robust Programming
This example illustrates the use of a StringBuilder to modify an existing string. Note that this requires an additional using declaration, since the StringBuilder class is a member of the System.Text namespace. Also, instead of defining a string and converting it to a character array, this is an example of creating a character array directly and initializing it.
This code produces the following output.
Some number of characters to
See Also
Tasks
How to: Create a Directory Listing
How to: Read and Write to a Newly Created Data File
How to: Open and Append to a Log File
How to: Read Characters from a String