Enumerated types contain a list of constants that can be addressed in integer values. The idea behind enumerated types is to create new data types that can take on only a restricted range of values. Moreover, these values are all expressed as constants rather than magic numbers in fact, there should be no need to know the underlying values. The names of the constants should be sufficient for the purposes of comparing values.
Example 1:
enum month { jan = 1, feb, mar, apr, may, jun, jul, aug, sep, oct, nov, dec };
enum month this_month;
this_month = feb;
In the above declaration, month is declared as an enumerated data type. It consists of a set of values, jan to dec. Numerically, jan is given the value 1, feb the value 2, and so on.
Example 2:
enum { Sunday, Monday, Tuesday, Wednesday, Thursday, Friday,
Saturday } weekday;