Unit Conversion Program using Classes

Welcome back guys, I hope you like my previous article, Introduction to Classes
in C++, in this article we will be further continuing our discussion on classes
in C++. We will not be discussing anything new on the topic though, just a simple
example program to elaborate more on Classes in C++.

In this article, I will show you a program based on classes, which converts
units of length from one to another. The program is simple and I do not think
there is any need for discussing it in detail.

The example program is given below:

  //C++ Program
  #include<iostream.h>

  class length
  {
   private:
   float in_meter, in_cm, in_inch;

   public:
   void input(float len,int ch);
   float output(int ch);
  };

  //---function definition starts---
  void length::input(float len,int ch)
  {
   switch(ch)
   {
    case 1://for meter
    in_meter=len;
    in_cm=in_meter*100;
    in_inch=in_cm*2.54;
    break;

    case 2://for cm
    in_cm=len;
    in_meter=in_cm/100;
    in_inch=in_cm/2.54;
    break;

    case 3://for inch
    in_inch=len;
    in_cm=in_inch*2.54;
    in_meter=in_cm/100;
    break;
   }
  }

  float length::output(int ch)
  {
   switch(ch)
   {
    case 1://for meter
    return in_meter;

    case 2://for cm
    return in_cm;

    case 3://for inch
    return in_inch;

    default://for other values
    return -1;
   }
  }
  //---function definition ends---

  void main(void)
  {
   int choice;
   float org_length;

   length length_obj;

   cout<<"Enter choice of unit:";
   cout<<"\n\n 1>Meter";
   cout<<"\n\n 2>Centimeter";
   cout<<"\n\n 3>Inch\n";
   cin>>choice;

   cout<<"\nEnter Length:";
   cin>>org_length;

   length_obj.input(org_length,choice);

   cout<<"\nLength in Meters: "<<length_obj.output(1);
   cout<<"\nLength in CMs : "<<length_obj.output(2);
   cout<<"\nLength in Inches: "<<length_obj.output(3);
   cout<<"\n\n";
  }

Enough for now, please check back for updates!