Implements IFormattable with switch statement : IFormattable : Class C# Examples

    
using  System;


public  class  Employee  :  IFormattable  {
        private  string  title;
        private  string[]  names;

        public  Employee(string  title,  params  string[]  names)  {
                this.title  =  title;
                this.names  =  names;
        }

        public  override  string  ToString()  {
                return  ToString("G",  null);
        }

        public  string  ToString(string  format,  IFormatProvider  formatProvider)  {
                string  result  =  null;

                if  (format  ==  null)  format  =  "G";
                switch  (format.ToUpper()[0])  {
                        case  'S':
                                result  =  names[0][0]  +  "."  +  names[names.Length  -  1];
                                break;
                        case  'P':
                                if  (title  !=  null  &&  title.Length  !=  0)  {
                                        result  =  title  +  ".";
                                }
                                break;

                        case  'I':
                                result  =  names[0];
                                break;
                        case  'G':
                        default:
                                result  =  names[0]  +  "  "  +  names[names.Length  -  1];
                                break;
                }
                return  result;
        }
}

public  class  MainClass  {
        public  static  void  Main()  {
                Employee  person  =  new  Employee("Mr",  "A",  "B",  "C",  "D");

                System.Console.WriteLine("{0:G},",  person);
                System.Console.WriteLine("{0:P},",  person);
                System.Console.WriteLine("{0:I},",  person);
                System.Console.WriteLine("{0},",  person);
                System.Console.WriteLine("{0:S},",  person);
        }
}