Contents

CS320/05 Questions UML Semantics

Using the UML

Give an example of how your project team described the semantics of its language.

Question 1a Model of Work in this class
Draw a UML diagram of the following classes and associations. Do not show any operations or attributes! Use the following class names: Student, PieceOfWork, Date, SequenceNumber, TypeOfWork. Relationships: Each student does several pieces of work. Each piece of work is done by one student on a particular date. Each piece of work is of a particular type. Each piece of work has a sequence number.
Question 1b
Add multiplicities and some role names to your diagram. Suggested role names: does, doneBy, etc..
Answer: [ 05a.html ]
In the following work as a group of 4-6 people. When you have a solution (or 2) wait for a chance to present the diagrams to the class.

Question 2a Model of the Java 1.0 AWT Class Library
Draw a UML diagram of the following classes and relationships (Note. these are taken from the Java library of classes): Integer and Float are sub-types of Object. All Applets are Panels, all Panels are Containers, all Containers are Components, and all Components are Objects. Some other Components are Buttons, Lists, and TextFields.
Answer: [ 05a.html ]
Question 2b
What do you add to the previous model to show that:
a Container can have any number of Components inside it?

Question 3a Compositions
Draw a UML diagram that uses composition (not attributes) to model the following C++ class:
```
 	class Wodget { public: float size; int knobs; string id; };
```
Answer: [ 05a.html ]
Question 3b
Draw a UML diagram that uses attributes (not composition) to model the C++ Wodget class above.
Answer: [ 05a.html ]

Question 4 Lab work/Web site
Draw a UML diagram of the part of your web site that is concerned with this class. Include the following ideas: Your_Home_Page, Your_CS320_Page, Lab_Page, Source_Code_Page.
Answer: [ 05a.html ]
Question 5 LISP Data
Draw a UML diagram of a Node where: A Node is either Empty, an Atom, or a Pair. Each Pair has two pointers to nodes called the car and cdr of the Pair.

Answer: [ 05a.html ]

Question 6 Syntax and Semantics
Which diagram (1,2,3) matches best each XBNF definition (alpha, beta, gamma) in this [ 05xab.png ] diagram.

Question 6a Syntax
For each syntax in [ 05xab.png ] give a string of "a"s and "b"s that fit that syntax and see if it also fits the other two. Which syntax is most general -- every string that fits the other two must also fit it.

Question 7 MiniCalc Syntax and Semantics
1. Expression::= Constant | Operation. All expressions can be evaluated and return an Int as a value.
```
 		123
```
```
 		1+2
```
2. Constant::= digit #digit. The evaluation of a constant returns its value. (This was defined in an earlier session).
```
 		123
```
3. evaluate("123") = 123.
4. Operation::= Constant Operator Expression. First the Expression is evaluated and then the Constant.
```
 		1+2
```
5. The Operator is applied to these values to calculate the value of the Operation.
6. Operator::= "+" | "-" | "*" | "/".
```
 		+
```
7. Each operator has an apply function that takes two values and returns a value.
```
 		apply(left:Int, right:Int): Int
```
  Draw a diagram, using the UML, that describes the classes of objects (Expression, Constant, Operation, Operator) plus their semantics. Do not show any syntax!
  Answer: [ 05a.html ]
OO Classroom Activity
To Be Announced: Given the UML description of .... students are asked to simulate various the objects collaborating.
Answers
[ 05a.html ]
Review
Think back over this class and grade your personal performance in terms of how much work you need to do on this topic before the final.

End