Enum Datatype consist of a set of named values. These values can be used in indexing expressions.

The idea behind enumerated datatype is to create new data types that can take on only a restricted range of values.

   enum enum-type-name { enumeration list } variable-list

#include <iostream.h>
int main()
  {
     enum Fruits{orange, guava, apple};
     Fruits myFruit;
     int i;
     cout << "Please enter the fruit of your choice(0 to 2)::";
     cin >> i;
     switch(i) 
       {
         case orange:
         cout << "Your fruit is orange";
         break;
         case guava:
         cout << "Your fruit is guava";
         break;
         case apple:
         cout << "Your fruit is apple";
         break;
      }
     return 0;
  }

    Please enter the fruit of your choice(0 to 2)::2
    Your fruit is apple

In the above example only the variable "i" is an integer. But using the enumeration the named values are used in a "switch case" statement with integer value "i".

This is how enum or enumerated datatype used in C++.