Enum and their Values

Question

What would be the value of Field.Format("%04d", ErrorCode) in the procedure below if the AErrorCode is ERR_NO_HEADER_RECORD_FOUND_ON_FILE?

Somewhere in a .h file:

enum AErrorCode
{
    ERR_UNKNOWN_RECORD_TYPE_CODE = 5001,
    ERR_NO_HEADER_RECORD_FOUND_ON_FILE,
    ERR_DUPLICATE_HEADER_RECORD_FOUND,

    ERR_THIRD_PARTY_LETTER_RECORD_HAS_A_ZERO_REFERRAL_AMOUNT = 5101,    

    ERR_CALL_OCA_UNKNOWN_PROBLEM = 5999
};

In some procedure:

void TADataset::SetErrorStatus(AErrorCode ErrorCode)
{
    NDataString Field;
    Field.Format("%04d", ErrorCode);
    AckRecord.SetField("oca_error_stat", "E");
    AckRecord.SetField("error_cd", Field);
}

To be pedantic, you should have a cast as in Field.Format("%04d", static_cast<int>(ErrorCode));. Technically, enums don't have to be the same size as an int, though they typically are in most implementations. — Adrian McCarthy
– Adrian McCarthy, Commented Sep 17, 2009 at 20:58

Khaled Alshaya · Accepted Answer · 2009-09-17 18:41:21Z

4

 ERR_NO_HEADER_RECORD_FOUND_ON_FILE == 5002

If you don't specify any value at all, it starts at 0 and increments the next element in the enum. If you specify a value, then it starts incrementing starting by the next element. Unless you reset the counter again by specifying another value for a successor element.

edited Sep 17, 2009 at 18:41

answered Sep 17, 2009 at 18:35

Khaled Alshaya

97.5k41 gold badges183 silver badges238 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Ralph Caraveo Over a year ago

It increments using whatever was previously defined + 1.

Amro Over a year ago

starts with 0, increments of 1, unless you specify the next value, then continue incrementing

Kirill V. Lyadvinsky · Accepted Answer · 2009-09-17 18:38:07Z

2

According C++ Standard 7.2/1:

<...>If the first enumerator has no initializer, the value of the corresponding constant is zero. An enumerator-definition without an initializer gives the enumerator the value obtained by increasing the value of the previous enumerator by one.

It means that ERR_NO_HEADER_RECORD_FOUND_ON_FILE equal to ERR_UNKNOWN_RECORD_TYPE_CODE+1.

answered Sep 17, 2009 at 18:38

Kirill V. Lyadvinsky

100k25 gold badges146 silver badges215 bronze badges

Collectives™ on Stack Overflow

Enum and their Values

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related