Добавил:

anolastanka Опубликованный материал нарушает ваши авторские права? Сообщите нам.

Вуз:

Bond University

Предмет:

[НЕСОРТИРОВАННОЕ]

Файл:

lafore_robert_objectoriented_programming_in_c

.pdf

Скачиваний:

Добавлен:

27.03.2023

Размер:

8.94 Mб

Скачать

☆

<<< < Предыдущая 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 9798 / 10498 99 100 101 102 103 104 > Следующая >>>

Answers to Questions and Exercises

945

public:

void getdata()

{

publication::getdata();

cout << “Enter number of pages: “; cin >> pages;

}

void putdata() const

{

publication::putdata();

cout << “\nPages: “ << pages;

}

};

////////////////////////////////////////////////////////////////

class tape : private publication // derived class

{

private:

float time; public:

void getdata()

{

publication::getdata();

cout << “Enter playing time: “; cin >> time;

}

void putdata() const

{

publication::putdata();

cout << “\nPlaying time: “ << time;

}

};

////////////////////////////////////////////////////////////////

int main()

{

book book1; // define publications tape tape1;

book1.getdata();	// get data for them
tape1.getdata();
book1.putdata();	// display their data
tape1.putdata();
cout << endl;
return 0;
}

Q E UESTIONS ANSWERS XERCISES AND TO

// ex9_2.cpp

//inheritance from String class #include <iostream>

Appendix G

946

#include <cstring>	//for strcpy(), etc.
using namespace std;

////////////////////////////////////////////////////////////////

class	String		//base class
{
protected:			//Note: can’t be private
	enum	{ SZ = 80 };	//size of all String objects
	char	str[SZ];	//holds a C-string
public:
	String()		//constructor 0, no args
	{ str[0] = ‘\0’; }
	String( char s[] )		//constructor 1, one arg
	{ strcpy(str, s); }		// convert string to String
	void display() const		//display the String
	{ cout << str; }
	operator char*()		//conversion function
	{ return str; }		//convert String to C-string
};

////////////////////////////////////////////////////////////////

class	Pstring : public String	//derived class
{
public:
	Pstring( char s[] );	//constructor
};
//--------------------------------------------------------------
Pstring::Pstring( char s[] )		//constructor for Pstring
{
if(strlen(s) > SZ-1)		//if too long,
	{
	for(int j=0; j<SZ-1; j++)	//copy the first SZ-1
	str[j] = s[j];	//characters “by hand”
	str[j] = ‘\0’;	//add the null character
	}
else		//not too long,
	String(s);	//so construct normally
}

////////////////////////////////////////////////////////////////

int main()
{		//define	String
Pstring	s1 = “This is a very long string	which is	probably “
	“no, certainly--going to exceed the limit set by SZ.”;
cout <<	“\ns1=”; s1.display();	//display String
Pstring	s2 = “This is a short string.”;	//define	String
cout <<	“\ns2=”; s2.display();	//display String
cout <<	endl;

return 0;

}

Answers to Questions and Exercises

//ex9_3.cpp

//multiple inheritance with publication class #include <iostream>

#include <string> using namespace std;

////////////////////////////////////////////////////////////////

class publication

{

private:

string title; float price;

public:

void getdata()

{

cout << “\nEnter title: “; cin >> title; cout << “ Enter price: “; cin >> price;

}

void putdata() const

{

cout << “\nTitle: “ << title; cout << “\n Price: “ << price;

}

};

////////////////////////////////////////////////////////////////

class sales

{

private:

enum { MONTHS = 3 }; float salesArr[MONTHS];

public:

void getdata();

void putdata() const;

}; //--------------------------------------------------------------

void sales::getdata()

{

cout << “ Enter sales for 3 months\n”; for(int j=0; j<MONTHS; j++)

{

cout << “ Month “ << j+1 << “: “; cin >> salesArr[j];

}

947

Q E UESTIONS ANSWERS XERCISES AND TO

Appendix G

948

//--------------------------------------------------------------

void sales::putdata() const

{

for(int j=0; j<MONTHS; j++)

{

cout << “\n Sales for month “ << j+1 << “: “; cout << salesArr[j];

}

////////////////////////////////////////////////////////////////

class book : private publication, private sales

{

private:

int pages; public:

void getdata()

{

publication::getdata();

cout << “ Enter number of pages: “; cin >> pages; sales::getdata();

}

void putdata() const

{

publication::putdata();

cout << “\n Pages: “ << pages; sales::putdata();

}

};

////////////////////////////////////////////////////////////////

class tape : private publication, private sales

{

private:

float time; public:

void getdata()

{

publication::getdata();

cout << “ Enter playing time: “; cin >> time; sales::getdata();

}

void putdata() const

{

publication::putdata();

cout << “\n Playing time: “ << time; sales::putdata();

}

};

Answers to Questions and Exercises

949

////////////////////////////////////////////////////////////////

int main()

{

book book1; // define publications tape tape1;

book1.getdata();	// get data for publications
tape1.getdata();
book1.putdata();	// display data for publications
tape1.putdata();
cout << endl;
return 0;
}

Chapter 10

Answers to Questions

1. cout << &testvar;

2.4 bytes

3.c

4.&var, *var, var&, char*

5.constant; variable

6.float* ptrtofloat;

7.name

8.*testptr

9.pointer to; contents of the variable pointed to by

10.b, c, d

11.No. The address &intvar must be placed in the pointer intptr before it can be accessed.

12.any data type

13.They both do the same thing.

14.

for(int j=0; j<77; j++)

cout << endl << *(intarr+j);

15.because array names represent the address of the array, which is a constant and can’t be changed

16.reference; pointer

Q E UESTIONS ANSWERS XERCISES AND TO

Appendix G

950

17.a, d

18.void func(char*);

19.

for(int j=0; j<80; j++) *s2++ = *s1++;

20.b

21.char* revstr(char*);

22.char* numptrs[] = { “One”, “Two”, “Three” };

23.a, c

24.wasted

25.memory that is no longer needed

26.p->exclu();

27.objarr[7].exclu();

28.a, c

29.float* arr[8];

30.b

31.0..9 at one end; 3..* at the other

32.b

33.false

34.a

Solutions to Exercises

//ex10_1.cpp

//finds average of numbers typed by user #include <iostream>

using namespace std;

int main()
{
float flarr[100];	//array for numbers
char ch;	//user decision
int num = 0;	//counts numbers input
do
{

	Answers to Questions and Exercises

cout << “Enter number: “;	//get numbers from user
cin >> *(flarr+num++);	//until user answers ‘n’
cout << “ Enter another (y/n)?	“;
cin >> ch;
}
while(ch != ‘n’);
float total = 0.0;	//total starts at 0
for(int k=0; k<num; k++)	//add numbers to total
total += *(flarr+k);
float average = total / num;	//find and display average
cout << “Average is “ << average <<	endl;
return 0;
}

//ex10_2.cpp

//member function converts String objects to upper case #include <iostream>

#include	<cstring>	//for	strcpy(),	etc
#include	<cctype>	//for	toupper()
using namespace std;

////////////////////////////////////////////////////////////////

class String	//user-defined string type
{
private:
char* str;		//pointer to string
public:
String(char* s)		//constructor, one arg
{
int length = strlen(s);		//length of string argument
str = new char[length+1];		//get memory
strcpy(str, s);		//copy argument to it
}
~String()		//destructor
{ delete str; }
void display()		//display the String
{ cout << str; }
void upit();		//uppercase the String
};
//--------------------------------------------------------------
void String::upit()		//uppercase each character
{
char* ptrch = str;		//pointer to this string
while( *ptrch )		//until null,
{
ptrch = toupper(ptrch);		//uppercase each character

951

Q E UESTIONS ANSWERS XERCISES AND TO

int main()

{

void bsort(char**, int);

Appendix G

952

ptrch++;	//move to next character
}

}

////////////////////////////////////////////////////////////////

int main()

{

String s1 = “He who laughs last laughs best.”;

cout << “\ns1=”;	//display string
s1.display();
s1.upit();	//uppercase string
cout << “\ns1=”;	//display string
s1.display();
cout << endl;
return 0;
}

//ex10_3.cpp

//sort an array of pointers to strings #include <iostream>

#include <cstring>		//for strcmp(), etc.
using	namespace std;
const	int DAYS = 7;	//number of pointers in array

//prototype

//array of pointers to char char* arrptrs[DAYS] = { “Sunday”, “Monday”, “Tuesday”,

“Wednesday”, “Thursday”, “Friday”, “Saturday” };

cout <<	“\nUnsorted:\n”;
for(int	j=0; j<DAYS; j++)	//display unsorted strings
cout	<< *(arrptrs+j) << endl;
bsort(arrptrs, DAYS);		//sort the strings
cout <<	“\nSorted:\n”;
for(j=0; j<DAYS; j++)		//display sorted strings
cout	<< *(arrptrs+j) << endl;
return 0;
}
//--------------------------------------------------------------
void bsort(char** pp, int n)		//sort pointers to strings
{

Answers to Questions and Exercises

953

void order(char**,	char**);	//prototype
int j, k;		//indexes to	array
for(j=0; j<n-1; j++)		//outer loop
for(k=j+1; k<n;	k++)	//inner loop	starts at outer
order(pp+j, pp+k);		//order the pointer contents
}

//--------------------------------------------------------------

void order(char** pp1, char** pp2) //orders two pointers

{	//if string in 1st is
if( strcmp(pp1, pp2) > 0)	//larger than in 2nd,
{
char* tempptr = *pp1;	//swap the pointers
pp1 = pp2;
*pp2 = tempptr;
}
}

//ex10_4.cpp

//linked list includes destructor #include <iostream>

using namespace std;

////////////////////////////////////////////////////////////////

struct link	//one element of list
{
int data;	//data item
link* next;	//pointer to next link
};

////////////////////////////////////////////////////////////////

class linklist	//a list of links
{
private:
link* first;	//pointer to first link
public:
linklist()	//no-argument constructor
{ first = NULL; }	//no first link
~linklist();	//destructor
void additem(int d);	//add data item (one link)
void display();	//display all links
};
//--------------------------------------------------------------
void linklist::additem(int d)	//add data item
{
link* newlink = new link;	//make a new link
newlink->data = d;	//give it data

Q E UESTIONS ANSWERS XERCISES AND TO

954	Appendix G

newlink->next = first;	//it points to next link
first = newlink;	//now first points to this
}
//--------------------------------------------------------------
void linklist::display()	//display all links
{
link* current = first;	//set ptr to first link
while( current != NULL )	//quit on last link
{
cout << endl << current->data;	//print data
current = current->next;	//move to next link
}
}
//--------------------------------------------------------------
linklist::~linklist()	//destructor
{
link* current = first;	//set ptr to first link
while( current != NULL )	//quit on last link
{
link* temp = current;	//save ptr to this link
current = current->next;	//get ptr to next link
delete temp;	//delete this link
}
}

////////////////////////////////////////////////////////////////

int main()
{
linklist li;	//make linked list
li.additem(25);	//add four items to list
li.additem(36);
li.additem(49);
li.additem(64);
li.display();	//display entire list
cout << endl;
return 0;
}

Chapter 11

Answers to Questions

1.d

2.true

<<< < Предыдущая 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 9798 / 10498 99 100 101 102 103 104 > Следующая >>>

Соседние файлы в предмете [НЕСОРТИРОВАННОЕ]

#
27.03.202313.92 Mб16-938a4_DesignforHowPeopleLearnVoicesThatMatter.epub
#
20.05.20235.11 Mб58CPlusPlusNotesForProfessionals.pdf
#
20.05.20236.12 Mб66CSharpNotesForProfessionals.pdf
#
20.05.20231.82 Mб36DotNETFrameworkNotesForProfessionals.pdf
#
27.03.20235.85 Mб51josuttis_nm_c20_the_complete_guide.pdf
#
27.03.20238.94 Mб51lafore_robert_objectoriented_programming_in_c.pdf
#
26.06.20235.15 Mб50lawrence_shaun_introducing_net_maui_build_and_deploy_crosspl.pdf
#
27.03.20237.26 Mб37roth_stephan_clean_c20_sustainable_software_development_patt-1.pdf
#
27.03.20237.26 Mб30roth_stephan_clean_c20_sustainable_software_development_patt.pdf
#
15.06.202424.85 Mб7ru_Абрамян М.Э. Visual С# на примерах.pdf
#
15.06.202482.06 Mб0ru_Зиборов В.В. Visual C 2012 на примерах.pdf