Summary

Key takeaways

1. We learned that enumeration attributes are string-valued attributes with a fixed list of possible string values. We frequently have to work with such attributes. Enumerations with records as instances also exist, with each record field including the name of the enumeration literals.

2. We learned how a record enumeration defines a record type with a unique field and a fixed list of records, and how to represent record enumeration in UML diagrams.

3. We learned that the values of extensible enumerations are internally represented by enumeration literals, and a new enumeration value can only be added at the end of the value list such that it can be assigned a new index integer without reassigning the indexes of other enumeration values. If we allow reassigning the enumeration, the mapping is disturbed.

4. We then saw how enumerations are represented in languages such as SQL and JS, and finally, we learned how to represent enumerations in a design model.