Enums

Enums are fixed size lists with unique names that you define. You can use them as custom modifiers for specific objects, or to hold a specific state in your smart contract. This is ideal for controlling the state of ICOs.

You declare them as follows:

enum Trees { RedTree, BlueTree, GreenTree, YellowTree }

Then, you create the enum variable:

Trees public myFavoriteTree = Trees.RedTree;

Note that you don't have to add a semicolon at the end of the enum declaration, but you do have to add it for the variable with the enum type that you just created.