What is the point of using ints as enums

Question

Why do a lot of people do enums this way:

public enum EmployeeRole
{
  None = 0,
  Manager = 1,
  Admin = 2,
  Operator = 3
}

instead of just doing:

public enum EmployeeRole
{
  None,
  Manager,
  Admin,
  Operator
}

Are there advantages?

Answer 1

Are there advantages?

Maintainability. Let's say these integer values end up persisted in a database. You don't want to add a new value to the enum in the future and have the values change because you insert a value in a way that shifts the unspecified values.

Clarity. Explicitness is a good thing. Let's say again we're reading integers out of a database from some legacy application. So the codes already have a specific meaning, and we want to explicitly line up with them. We could say

public enum EmployeeRole {
    None,
    Manager,
    Admin,
    Operator
}

and maybe that lines up exactly with the legacy specification or we could say

public enum EmployeeRole {
    None = 0,
    Manager = 1,
    Admin = 2,
    Operator = 3
}

and now it is easier to read whether or not we line up with the legacy specification.

Answer 2

It is useful when you have a contract elsewhere. If you store the enum in a database you want to type the numbers explicitly to be sure you don't accidentally renumber the enum by inserting a new item in the middle.

Answer 3

It explicits defines a value rather than letting the compiler handle it at compile time. In the case you provided, it really serves no point other than being readable and and well-defined. It doesn't hurt anything and results in the same MISL as not explicitly setting them. However, in cases where your enums relate to specific values that are not auto-incremented as the above case is, this kind of explicit definition comes in very handy.

public enum MyEnum
{

    First = 1,
    Second = 2,
    Eleventh = 11

}