C#

StringBuilder s = new StringBuilder();
string text; // No need to assign the variable to a string that's then thrown away
while ((text = reader.readLine()) != null) {
   if ( <condition> )
      s.Append(text).Append('\n');
}

StringBuilder sb;
string text = "abc";
int x, y;
long startTime, endTime;
 <br>
startTime = DateTime.Now.Ticks;
for(y = 0; y < 5000; y++) {
    sb = new StringBuilder(10000);
    for (x = 0; x < 250; x++) {   
        sb.Append(text).Append('\n');
        sb.Append(text).Append('\n');
        sb.Append(text).Append('\n');
        sb.Append(text).Append('\n');
        sb.Append(text).Append('\n');
        sb.Append(text).Append('\n');
        sb.Append(text).Append('\n');
        sb.Append(text).Append('\n');
        sb.Append(text).Append('\n');
        sb.Append(text).Append('\n');
    }
}
endTime = DateTime.Now.Ticks;
Console.WriteLine(((endTime - startTime) / 10000) + " ms using Append()");
 <br>
startTime = DateTime.Now.Ticks;
for(y = 0; y < 5000; y++) {
    sb = new StringBuilder(10000);
    for (x = 0; x < 250; x++) {
        sb.AppendFormat("{0}\n", text);
        sb.AppendFormat("{0}\n", text);
        sb.AppendFormat("{0}\n", text);
        sb.AppendFormat("{0}\n", text);
        sb.AppendFormat("{0}\n", text);
        sb.AppendFormat("{0}\n", text);
        sb.AppendFormat("{0}\n", text);
        sb.AppendFormat("{0}\n", text);
        sb.AppendFormat("{0}\n", text);
        sb.AppendFormat("{0}\n", text);
    }
}
endTime = DateTime.Now.Ticks;
Console.WriteLine(((endTime - startTime) / 10000) + " ms using AppendFormat()");

if (aLOV == null)
  aLOV = new MyDataGrid(); // Or whatever your class is

if (aForm.Controls.Contains(aLOV))
  aForm.Controls.Remove(aLOV);
else
  aForm.Controls.Add(aLOV);

// Somewhere in your form or other class, define...
[DllImport("user32.dll")]
private static extern bool GetWindowPlacement(IntPtr hWnd, ref WindowPlacement placement);
// Later as a nested struct or internal struct...
internal struct WindowPlacement
{
  public int length;
  public int flags;
  public int showCmd;
  public POINT ptMinPosition;
  public POINT ptMaxPosition;
  public RECT rcNormalPosition;
}
internal POINT
{
  public long x;
  public long y;
}
internal RECT
{
  public long left;
  public long top;
  public long right;
  public long buttom;
}
// When you call the function...
WindowPlacement placement = new WindowPlacement();
placement.cbSize = Marshal.SizeOf(placement);
if (GetWindowPlacement(this.Handle, ref placement))
{
  int nCmdShow = placement.showCmd;
  // See the SW_* #defines in WinUser.h for values.
}

public class NegativeArray
{
    private Array myArray;
    private int indexOffset;

    public object this[int i]
    {
        get
        {
            return myArray[i+indexOffset];
        }
        set
        {
            myArray[i+indexOffset] = value;
        }
    }
    // You'd have to fill in the rest yourself ;)
}