Answers to Questions in Lecture/Discussion 5
- Draw a UML diagram of the following classes and relationships::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. Note. This
example is part of the Java "AWT".
What do you add to it to show that a Container can have any number of Components inside it?
Question 3
Draw a UML diagram that uses composition to model the following C++ class: - class Wodget { public: float size; int knobs; string id; };
Draw a UML diagram that uses attributes to model the following C++ class:
- class Wodget { public: float size; int knobs; string id; };
Question 4
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, WWW Pages in general.
(The above is non-standard!)
Question 5
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. (This is the structure of LISP!)
This is a simple example of the Composite pattern. The composite pattern is in the handout. Use it in your project!
-
MiniCalc has simple integer Expressions:
- Expression::= Constant | Operation. All expressions can be
evaluated returning a number.
- Constant::= digit #digit. The evaluation of a constant
returns its value.
- Operation::= Constant Operator Expression.
- Operations are evaluated by applying the operator to the
Constant and the result of evaluating the Expression.
- Operator::= "+" | "-" | "*" | "/".
- Each operator has an apply function that takes two values
and returns an int value.
Hint:
Answer: [ 06/ole7.gif ]
Specifications using the Object Constraint Language
Constant::evaluate()
result self.value
Operation::evaluate()
result operator.apply( constant.evaluate(), expression.evaluate())
Addition::apply( i:Int, j:Int)
result i+j
Subtraction::apply( i:Int, j:Int)
result i-j
Write, in the same format as the above, the missing specifications for methods.C++ Code for MiniCalc
Have look at [ minicalc.cpp ] that is the C++ code for 6 of the above classes plus a simple set of tests. Down load and test it.Add and test classes for Multiplication and Division.
If you have a lot of spare time, add a lexer and a parser.
. . . . . . . . . ( end of section Question 6 Minicalc) <<Contents | End>>
- Expression::= Constant | Operation. All expressions can be
evaluated returning a number.
Question 1
Draw a UML diagram of the following classes and associations. 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.Add multiplicities and some role names to your diagram. Suggested role names: does, doneBy, ...?
