Reading a UML Class Diagram

UML class overview


  • scope is indicated as + public, - private, (# protected, ~ package - these are not focused on in CS149).
  • The arg list is a list of parameter types (e.g., int, double, String) it can also include type after a :
  • Class (i.e. static) methods and fields are indicated by underlining
  • Constant (i.e. final) fields are indicated via naming convention: constants should be in ALL_CAPS

Lines between classes indicate relationships as follows:

UML relationships

and can have numbers indicating instances of or 'multiplicity' as follows:

0 No instances (rare)
0..1 No instances, or one instance
1 Exactly one instance
1..1 Exactly one instance
0..* Zero or more instances
* Zero or more instances
1..* One or more instances

For example:

Credit Card UML Diagram

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