Compiler Error CS0100

The parameter name 'parameter name' is a duplicate

A method declaration used the same parameter name more than once. Parameter names must be unique in a method declaration. For more information, see Methods (C# Programming Guide).

The following sample generates CS0100:

// CS0100.cs
namespace x
{
   public class a
   {
      public static void f(int i, char i)   // CS0100
      // try the following line instead
      // public static void f(int i, char j)
      {
      }

      public static void Main()
      {
      }
   }
}