Csharp/C Sharp by API/System/IFormattable

implements IFormattable

<source lang="csharp">

using System; using System.Globalization; public sealed class ComplexNumber : IFormattable {

   public ComplexNumber( double real, double imaginary ) {
       this.real = real;
       this.imaginary = imaginary;
   }
   public override string ToString() {
       return ToString( "G", null );
   }
   public string ToString( string format, IFormatProvider formatProvider ) {
       string result = "(" + real.ToString(format, formatProvider) + " " + real.ToString(format, formatProvider) + ")";
       return result;
   }
  
   private readonly double real;
   private readonly double imaginary;

} public sealed class MainClass {

   static void Main() {
       ComplexNumber num1 = new ComplexNumber( 1.12345678, 2.12345678 );
       
       Console.WriteLine( "US format: {0}", num1.ToString( "F5", new CultureInfo("en-US") ) );
       Console.WriteLine( "DE format: {0}", num1.ToString( "F5", new CultureInfo("de-DE") ) );
       Console.WriteLine( "Object.ToString(): {0}",num1.ToString() );
   }

}

 </source>