Is the following syntax is correct for an enum?

问题

enum  {
  ValidationLoginFailed=2000,
  ValidationSessionTokenExpired=2001,
  ValidationSessionTokenInvalid=2002,
  ValidationEmailNotFound=2003
  ValidationSucccesMIN=ValidationLoginFailed,
  ValidationSucccesMAX=ValidationEmailNotFound,
  ValdationValidSuccessCode=9999,
  ValdationInvalidCode=10000

}; 
typedef int ValidationStatusCodes;

please help me out.

回答1:

In your code, ValidationStatusCodes means int, not your anonymous enum type. So they aren't actually connected in any way.

However, since your enum contains int values, you could say that there's some sort of relation. You can pass the names of the enumerated values and they will be considered of the int or ValidationStatusCodes type.

By the way, Apple does something similar to what you do, except they typedef their collective names to NSInteger or NSUInteger instead of int or uint. See this question for an example.

With all that said, a more common practice is to typedef your custom type name directly to the anonymous enum, like this:

typedef enum {
    ValidationLoginFailed = 2000,
    ValidationSessionTokenExpired = 2001,
    ValidationSessionTokenInvalid = 2002,
    ValidationEmailNotFound = 2003
    ValidationSuccessMIN = ValidationLoginFailed,
    ValidationSuccessMAX = ValidationEmailNotFound,
    ValdationValidSuccessCode = 9999,
    ValdationInvalidCode = 10000
} ValidationStatusCodes;

来源：https://stackoverflow.com/questions/5785965/is-the-following-syntax-is-correct-for-an-enum