CSCI 152 Hierarchical (Nested) Structures

// GLOBAL TYPE DECLARATIONS

1 struct Date

2 {

3 int month;

4 int day;

5 int year;

6 };

7 struct Machine

8 {

9 int id;

10 bool serviceContract;

11 float failRate;

12 Date lastServiced;

13 int downDays;

14 Date purchaseDate;

15 float cost;

16 float deprValue;

17 };

// LOCAL VARIABLE DECLARATIONS

18 Date yesterday,

19 today;

20 Machine press;

21 Machine station [100];

The following statements demonstrate references to fields (fully qualified names must be used for all field identifiers):

22 cout << "Date: " << today.month << "/" << today.day << "/" << today.year

<< endl;

23 cout << "Machine # " << press.id << endl;

24 cout << "Purchase date: " << press.purchaseDate.month << "/"

25 << press.purchaseDate.day << "/"

26 << press.purchaseDate.year << endl;

27 cout << "Original cost = $" << setprecision(2) << press.cost << endl;

28 cout << "Depreciation value = $" << press.deprValue << endl;

29 cout << "Total down days since purchase = " << press.downDays << endl;

30 cout << "Last serviced: " << press.lastServiced.day << " "

31 << press.lastServiced.month << " "

32 << press.lastServiced.year << endl;

33 if (press.failRate > 0.10)

34 cout << "Excessive downtime\n";

35 if (! press.serviceContract) // or if (press.serviceContract == false)

36 cout << "Service contract has expired\n";

The only defined operations for structure variables (the entire structure) of the same type are

• assignment
• pass as a parameter to a function (either by value or by reference)
• return by a function

37 press.lastServiced = today;

is equivalent to:

38 // press.lastServiced.month = today.month;

39 // press.lastServiced.day = today.day;

40 // press.lastServiced.year = today.year;

1 station[5] = press;

is equivalent to:

2 station[5].id = press.id;

3 station[5].serviceContract = press.serviceContract;

4 station [5].failRate = press.failRate;

5 station[5].lastServiced.month = press.lastServiced.month;

6 station[5].lastServiced.day = press.lastServiced.day;

7 station[5].lastServiced.year = press.lastServiced.year;

8 station [5].downDays = press.downDays;

9 station[5].purchaseDate.month = press.purchaseDate.month;

10 station[5].purchaseDate.day = press.purchaseDate.day;

11 station[5].purchaseDate.year = press.purchaseDate.year;

12 station [5].cost = press.cost;

13 station [5].deprValue = press.deprValue;

Arrays as fields in a structure

// Type declarations:

struct COURSE

{

string dept;

int courseNum;

int section;

char letterGrade;

};

struct ADDRESS

{

string street;

string cityState;

string zipCode;

};

struct STUDENT

{

string name;

ADDRESS localAddress;

ADDRESS permanentAddress;

COURSE grades[10];

};

// Variable declarations:

COURSE myCourse;

ADDRESS myAddress;

STUDENT aStudent;

STUDENT students[100];

// To refer to: Use this name:

The number of my course: myCourse.courseNum

My zip code: myAddress.zipCode

The name of the first student: students[0].name

The initial of the second student: students[1].name[0]

The fourth grade of the tenth student: students[9].grades[3].letterGrade

The local address (a record) of the last student: students[99].localAddress

The zip code of the local address of the first student: students[0].localAddress.zipCode