Spring 2008

Mark Fontenotmfonten@engr.smu.edu

CSE 2341 - HonorsPrinciples of Computer Science I

Note Set 31

Take Note!!!

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Next Tuesday,January 22, 2008

Follows a Monday Schedule!!!

Quick Look

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Activity Diagrams and the UMLUse default and overloaded constructorsDeclare and work with an array of objectsValidate user input from within a class

UML®

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“helps you specify, visualize, and document models of software systems, including their structure and design”*

Used heavily in industry to design software (and other things as well)

Can be used to explore a current code base by reverse engineering to UML models

UML specifies 13 different diagrammatic tools to use in design of system architecture

* Siegel, Jon. Introduction to OMG's Unified Modeling Language™ (UML®), http://www.omg.org/gettingstarted/what_is_uml.htm. July 2005

Our First UML Diagram – Activity Diagram

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Activity Diagram models logiccan be used at various levels of detail (30,000 foot view or

microscopic view of)Somewhat similar to flowcharting

Sample Activity Diagram

Main Activity Diagram Artifacts

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Initial Node – indicates starting point of logic

Final Node – indicates stopping point of logic

Activity – rounded rectangle – represents the activities that are taking place

Flow - arrow indicating flow of logic

Decision – Diamond with one flow entering and two or more exiting

Ambler, Scott. UML 2 Activity Diagrams, August 20 2006. http://www.agilemodeling.com/artifacts/activityDiagram.htm

Main Activity Diagram Artifacts (2)

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Merge – Diamond – two or more flows entering and one exiting

Condition – text in square brackets indicated a condition that must be satisfied to traverse its flow.

[credentials valid] [credentials not valid]

Ambler, Scott. UML 2 Activity Diagrams, August 20 2006. http://www.agilemodeling.com/artifacts/activityDiagram.htm

Examples with pseudocode

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If x is greater than 60print “YOU PASSED”

Examples with pseudocode

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Initialize value to – 3Loop while value is less than 10

value = value + 2

Overloaded Constructors

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#ifndef INVENTORYITEM_H#define INVENTORYITEM_H#include <cstring>using namespace std;class InventoryItem{private:char *description;int units;

public:InventoryItem()

{ description = new char[51]; }InventoryItem(char *desc)

{ description = new char[strlen(desc)+1]; strcpy(description, desc);

}

Inve

ntoryItem.h

Overloaded Constructors

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InventoryItem(char *desc, int u) { description = new char [strlen(desc) + 1]; strcpy(description,desc); units = u; } ~InventoryItem() { delete[] description; } void setDescription(char *d) { strcpy(description, d); } void setUnits (int u) { units = u; } char *getDescription() { return description; } int getUnits() { return units; }};#endif

Inve

ntoryItem.h

Declaring Objects

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Because of the overloaded constructors, can instantiate in different ways

InventoryItem ii;InventoryItem ii2(“Wrench”);InventoryItem ii3(“Hammer”, 10);

Constructors and Destructors

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A class can only have one default constructorA class can have any number of overloaded constructorsA class can have only one destructor

Objects and Arrays

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Possible to declare arrays of objects

Default constructor would be called for each element in the array.

InventoryItem store[10];

Objects and Arrays

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May use initialization lists to call overloaded constructors

Square tres[3] = {5, 6, 10};

InventoryItem store[3] = { “Wrench”, “Hammer”, “Pliers” };

Objects and Arrays

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Need more complex initialization list if number of args to constructor is greater than 1

InventoryItem inventory[3] = {

“Hammer”, InventoryItem(“Wrench”,17), }

First Element

Second Element

Third Element- Which constructor????

Objects and Arrays

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InventoryItem inventory[3] = {

InventoryItem(“Hammer”, 12), InventoryItem(“wrench”, 17), InventoryItem(“pliers”, 10) };

for (int i =0; i < 3; i++){ cout << inventory[i].getDescription(); cout << inventory[i].getUnits();}

Design Time

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Design an array class. The class should create an array of integers of any size at runtimeperform bounds checkingallows setting of a particular element of an arrayretrieves a particular element from the array

Intlist

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#ifndef INTLIST_H#define INTLIST_Hclass IntList{ private: int *list; int numElements; bool isValid(int);public: IntList(int); ~IntList();

bool set(int, int);bool get(int, int &);

};#endif

Intlist.h

Intlist

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#include “IntList.h”

IntList::IntList (int size){ list = new int[size]; numElements = size; for (int ndx =0; ndx < size; ndx++) list[ndx] = 0;}

IntList::~IntList(){ delete [] list;}

Intlist.cpp

Intlist

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bool IntList::isValid(int element){ if (element < 0 || element >= numElements) return false; else return true;}bool IntList::set(int element, int value){ if (isValid(element)) { list[element] = value; return true; } else return false;}

Intlist.cpp

Intlist

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bool IntList::get(int element, int &value){ if (isValid(element)) { value = list[element]; return true; } else return false;}

Intlist.cpp

Take Note!!!

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Next Tuesday,January 22, 2008

Follows a Monday Schedule!!!

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