Composition - The object only exists if the parent object exists, if the parent object is deleted then so is the child object. The zoo object owns the compound object. If the zoo object is deleted then the compound object is also deleted.
public class Zoo {
private Compound dogArea = new Compound();
}
Inheritance A way of forming new classes based on existing classes. Has a "is-a" relationship.
Polymorphism - A concept in object oriented programming. Method overloading and method overriding are two types of polymorphism. @@ -1193,7 +1193,7 @@ A way of forming new classes based on existing classes. Has a "is-a" relationshi }
The super keyword called the parent class' constructor.
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What is the difference between an abstract class and an interface - Java abstract class can have instance methods that implement a default behaviour. May contain non-final variables. - Java interfaces have methods that are implicitly abstract and cannot have implementations. Variables are declared final by default.
diff --git a/lectures/dms/02_uml/index.html b/lectures/dms/02_uml/index.html index b5b2ef3..804da87 100644 --- a/lectures/dms/02_uml/index.html +++ b/lectures/dms/02_uml/index.html @@ -1158,7 +1158,7 @@
Use case diagrams
<<include>>- multiple use cases share a piece of same functionality which is placed in a separate use case.
<<extend>> - Used when activities might be performed as part of another activity but are not mandatory for a use case to run successfully.
Use case diagram of a fleet logistics management company
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Base Path - The optimistic path (best case scenario)
Alternative Path - Every other possible way the system can be used/abused. Includes perfectly normal alternate use, but also errors and failures.
Use Case: Borrow copy of book