Question

What is the use of the enum keyword ? Where can we use enumerated data-type?
Can anyone explain with an example?

Answer 1

Enums are enumerators (ok, trivial) treated always as integers, and they are used to put in order something you could use later, like common values or indexes. But, as the name says, they are enumerated, always ascending, like:

enum myenum {
January, February, March, April, May, June, July, August, September, October, November, December
};

Then, if you have an array, say:

int months[12][30];

You can call your months using:

months[March][...];

Also, if you declare:

enum myenum {  January = 1, February, March, ..., };

This your program will start the counter of the enumeration from 1 and so on.

Finally, about this last rule: you can set initial values as you want, e.g., 10, 20, 30, 42 etc., but you can also set one of the enumerated values and let others be sorted by default.