The use of enum without a variable name

Question

I understand the first one but the second one? When and why would you do that?

enum cartoon { HOMER, MARGE, BART, LISA, MAGGIE };  enum { HOMER, MARGE, BART, LISA, MAGGIE }; 

Answer 1

you can define such enum in a class, which gives it a scope, and helps expose class's capabilities, e.g.

class Encryption { public:   enum { DEFAUTL_KEYLEN=16, SHORT_KEYLEN=8, LONG_KEYLEN=32 };   // ... };  byte key[Encryption::DEFAUTL_KEYLEN]; 

Answer 2

This simply creates constant expressions that have the respective values, without a type other than simply int, so you can't use an unnamed enum as a type for anything, you will have to simply accept an int and then do comparison with the constant.

Something like this:

void doSomething(int c); 

Versus something like this:

void doSomething(cartoon c); 

By the way, your implementation would be the same, so in the case of unnamed enums, the only real drawback is strong typing.