实验11_参考答案

1、实验11类与对象2（2）请将自己报告部分，文字和程序代码，加粗完成下面实验内容和实验要求。 自测练习 1编程练习：简易计算器编写一个SimpleCalculator类，包含一些public方法来对两个double型变量进行加减乘除运算。实例输出： 将下面程序代码补充完整，并运行（注意：共有3个文件：SimpleCalculator.h, SimpleCalculator.cpp, CalcDriver.cpp，此3个文件放到一个工程中进行调试）/ SimpleCalculator.hclass SimpleCalculator public:/*补充 add方法的原型声明 */double s

2、ubtract ( double, double ) const;double multiply( double, double ) const;/* 补充divide方法的原型声明 */;/ SimpleCalculator.cpp#include “SimpleCalculator.h”/ 补充add方法的定义double SimpleCalculator:subtract( double a, double b ) constreturn a b;double SimpleCalculator:multiply( double a, double b ) constreturn a *

3、b;/补充 divide方法的定义/ CalcDriver.cpp#include < iostream>#include “SimpleCalculator.h”using namespace std;int main()double a=10.0;double b=20.0;/ 声明SimpleCalculator类的对象sccout << “The value of a is: “<<a<<endl;cout <<”The value of b is: “ << b<< endl;/*写一条语句，声明变量

4、addition，通过SimpleCalculator类对象sc计算a+b，并将结果赋值给addition变量 */cout << “Adding a and b yields “<< addition << endl;double substraction = sc.substract ( a, b );cout << “Subtracting b from a “<< subtraction << endl;double multiplication = sc.multiply ( a, b );cout <&l

5、t; “Multiplying a and b yields “<< multiplication << endl;/*写一条语句，声明变量division，通过SimpleCalculator类对象sc计算a/b，并将结果赋值给division变量 */cout << “Dividing a by b yields “<< division<< endl;return 0;补充后代码：/ SimpleCalculator.hclass SimpleCalculator public:/*补充 add方法的原型声明 */double

6、add( double, double ) const;double substract( double, double ) const;double multiply( double, double ) const;double divide( double, double ) const;/* 补充divide方法的原型声明 */;/ SimpleCalculator.cpp#include "SimpleCalculator.h"double SimpleCalculator:add(double a,double b)constreturn a + b;double

7、 SimpleCalculator:substract( double a, double b ) constreturn a - b;double SimpleCalculator:multiply( double a, double b ) constreturn a * b;double SimpleCalculator:divide(double a,double b)constreturn a / b;/ CalcDriver.cpp#include < iostream>#include "SimpleCalculator.h"using names

8、pace std;int main()double a=10.0;double b=20.0;SimpleCalculator sc;/ 声明SimpleCalculator类的对象sccout << "The value of a is: "<<a<<endl;cout <<"The value of b is: " << b<< endl;/*写一条语句，声明变量addition，通过SimpleCalculator类对象sc计算a+b，并将结果赋值给addition变量 */d

9、ouble addition = sc.add ( a, b );cout << "Adding a and b yields "<< addition << endl;double substraction = sc.substract ( a, b );cout << "Subtracting b from a "<< substraction << endl;double multiplication = sc.multiply ( a, b );cout << &

10、quot;Multiplying a and b yields "<< multiplication << endl;/*写一条语句，声明变量division，通过SimpleCalculator类对象sc计算a/b，并将结果赋值给division变量 */double division = sc.divide (a,b);cout << "Dividing a by b yields "<< division<< endl;return 0;运行结果：修改上面创建的类，在SimpleCalculator

11、类中创建一个名为answer的private型数据成员，执行某项运算后，将运算结果赋给answer。增加一个名为getAnswer的函数，其功能为检索对象的最后一次算术运算结果。同时，再给SimpleCalculator类增加一个构造函数，将answer的值初始化为0.修改后代码：/ SimpleCalculator.hclass SimpleCalculator public:/*补充 add方法的原型声明 */SimpleCalculator();double add( double, double ) ;double substract( double, double ) ;double

12、 multiply( double, double ) ;double divide( double, double ) ;double getAnswer()const;/* 补充divide方法的原型声明 */private:double answer;/ SimpleCalculator.cpp#include "SimpleCalculator.h"SimpleCalculator:SimpleCalculator()answer=0;double SimpleCalculator:add(double a,double b)answer = a + b;retur

13、n answer;double SimpleCalculator:substract( double a, double b ) answer = a - b;return answer;double SimpleCalculator:multiply( double a, double b ) answer = a * b;return answer;double SimpleCalculator:divide(double a,double b)answer = a / b;return answer;double SimpleCalculator:getAnswer() constret

14、urn answer;/ CalcDriver.cpp#include < iostream>#include "SimpleCalculator.h"using namespace std;int main()double a=10.0;double b=20.0;SimpleCalculator sc;/ 声明SimpleCalculator类的对象sccout << "The value of a is: "<<a<<endl;cout <<"The value of b is:

15、 " << b<< endl;/*写一条语句，声明变量addition，通过SimpleCalculator类对象sc计算a+b，并将结果赋值给addition变量 */sc.add ( a, b );cout << "Adding a and b yields "<<sc.getAnswer()<< endl;sc.substract ( a, b );cout << "Subtracting b from a "<<sc.getAnswer()<<

16、; endl;sc.multiply ( a, b );cout << "Multiplying a and b yields "<<sc.getAnswer()<< endl;/*写一条语句，声明变量division，通过SimpleCalculator类对象sc计算a/b，并将结果赋值给division变量 */sc.divide (a,b);cout << "Dividing a by b yields "<<sc.getAnswer()<< endl;return 0;运行结

17、果修改程序，给SimpleCalculator类增加input函数，使用户可以自己输入两个double型变量。函数将输入的值存储在类新增private成员数据a和b中。再给SimpleCalculator类创建两个构造函数，一个没有参数，将a和b初始化为0；另一个将输入的两个double型变量作为参数，并将a和b初始化为输入的值。最后，创建一个函数printValues，将a和b的值显示出来。修改后代码：/ SimpleCalculator.hclass SimpleCalculator public:/*补充 add方法的原型声明 */SimpleCalculator();double ad

18、d( double, double ) ;double substract( double, double ) ;double multiply( double, double ) ;double divide( double, double ) ;double getAnswer()const;void input(double ,double );void printValues();/* 补充divide方法的原型声明 */private:double answer;double a;double b;/ SimpleCalculator.cpp#include < iostrea

19、m>#include "SimpleCalculator.h"SimpleCalculator:SimpleCalculator()answer=0;a=0;b=0;double SimpleCalculator:add(double a,double b)answer = a + b;return answer;double SimpleCalculator:substract( double a, double b ) answer = a - b;return answer;double SimpleCalculator:multiply( double a,

20、double b ) answer = a * b;return answer;double SimpleCalculator:divide(double a,double b)answer = a / b;return answer;double SimpleCalculator:getAnswer() constreturn answer;void SimpleCalculator:input(double pA,double pB)a=pA;b=pB;void SimpleCalculator:printValues()std:cout<<"a: "<

21、;<a<<"tb: "<<b<<std:endl;/ CalcDriver.cpp#include < iostream>#include "SimpleCalculator.h"using namespace std;int main()double a=10.0;double b=20.0;SimpleCalculator sc;/ 声明SimpleCalculator类的对象sccout << "The value of a is: "<<a<&

22、lt;endl;cout <<"The value of b is: " << b<< endl;/*写一条语句，声明变量addition，通过SimpleCalculator类对象sc计算a+b，并将结果赋值给addition变量 */sc.add ( a, b );cout << "Adding a and b yields "<<sc.getAnswer()<< endl;sc.substract ( a, b );cout << "Subtracting

23、 b from a "<<sc.getAnswer()<< endl;sc.multiply ( a, b );cout << "Multiplying a and b yields "<<sc.getAnswer()<< endl;/*写一条语句，声明变量division，通过SimpleCalculator类对象sc计算a/b，并将结果赋值给division变量 */sc.divide (a,b);cout << "Dividing a by b yields "<

24、;<sc.getAnswer()<< endl;sc.printValues();sc.input(20.0,10.0);sc.printValues();return 0;运行结果2【程序输出练习】有如下的Time类定义class Time public:Time( );/ constructorvoid setTime ( int, int, int );/ set hour minute secondvoidPrintMilitary ( );/ print military time formatvoid PrintStandard ( );/ print stand

25、ard time formatprivate:int hour;/ 0-23int minute;/ 0-59int second;/ 0-59;Time:Time() hour=minute=second=0;void Time:setTime( int h, int m , int s)hour = (h>=0 && h<24 )?h:0;minute=(m>=0 && m<60)?m:0; second=(s>=0 && s<60)?s:0;void Time:printMilitary()cout &l

26、t;<( hour<10?”0”: “”) <<hour <<”:”<<(minute<10 ? “0” : “”)<<minute;void Time:printStandard()cout << ( ( hour=0 | hour =12) ? 12 : hour % 12 )<<”:” << ( minute<10 ? “0” : “”) << minute<<”:” << ( second<10 ? “0” : “”) <<

27、second<< ( hour < 12 ? “AM” : “PM” ); 假设采用中的Time类定义，以下语句的输出结果是什么？（请阅读分析，不要运行代码） Time t (3, 4, 5);编译出错，没有上述构造函数，应该是Time t;t.setTime(3,4,5)。并且后三问最好按照(3,4,5)进行t.printStandard();cout<<endl;输出结果：3:04:05AMt.printMilitary();cout<<endl;输出结果：03:04t.setTime(99,3,4);t.printMilitary();cout&

28、lt;<endl;输出结果：00:03写出下面Time类的两个构造函数的名字和功能，正确的Time类定义是否可以同时包含以下的两个构造函数？如果不可以，请说明原因。Time( int h=0, int m = 0, int s = 0);Time ( );答：不可以。当创建无参数对象的时候，比如Time t;，Time( int h=0, int m = 0, int s = 0);和Time ( );会被编译器当成同样的函数，不知道要调用哪个函数。3.【程序调试练习】下列程序运行不正确。请改正其中的语法错误使得程序可以编译成功。程序编译后，请比较输出结果与实例输出，并对可能存在的逻辑错

29、误进行修改。实例输出显示了程序如果正确应该输出的结果。实例输出：错误的代码：（注意：共有3个文件：card.h, card.cpp, debugging.cpp，此3个文件放到一个工程中进行调试）第一个文件card.h#ifndef CARD_H#define CARD_Hclass Cardpublic:void Card();void Card( int s, int v);void Card();void setSuit( int s);void setValue( int v);int getSuit() const;int getValue() const;void print()

30、const;private:int suit=4;int value=1;bool validCard() const;#endif第二个文件card.cpp#include <iostream>using namespace std;void Card:Card() suit=4; value=1;Card:Card(int s, int v) suit=s; value=v;Card:Card() cout<< "The destructor has been invokedn"void Card:setSuit(int s) suit=s;vo

31、id Card:setValue( int v) value=v; void print()if (!validCard() ) cout << "This card is not validn"return;cout<<"This is the: "switch(value)case 1: cout <<"Ace "break;case 11:cout<<"Jack "break;case 12:cout<<"Queen "break

32、;case 13:cout << "King "breawk;default:cout<<value<<" "switch(suit) case 1:cout <<"of clubsn"break;case 2:cout<<"of diamondsn"break;case 3:cout<<"of heartsn"break;case 4:cout<<"of spadesn"break;defa

33、ult:cout<<"ninvalid suitn"int Card:getSuit() return suit;int Card:getValue() return value;bool validCard()return value>=1 && value <=13 && suit >=1 && suit <=4;void Card:setValue(int v) value=v;void print()if (!validCard()cout<<"This car

34、d is not validn"return;cout <<"This is the: "switch(value)case 1: cout <<"Ace "break;case 11:cout<<"Jack "break;case 12:cout<<"Queen "break;case 13:cout << "King "break;default:cout<<value<<" "

35、switch(suit) case 1:cout <<"of clubsn"break;case 2:cout<<"of diamondsn"break;case 3:cout<<"of heartsn"break;case 4:cout<<"of spadesn"break;default:cout<<"ninvalid suitn"int Card:getSuit() return suit;int Card:getValue()

36、return value;bool validCard()return value>=1 && value <=13 && suit >=1 && suit <=4;第三个文件debugging.cpp#include <iostream>using namespace std;int main()Card c1, c2(3, 4), c3(1, 14);Card *p1=&c2;c1.print();c2.print();c3.print();p1->print();cout<<en

37、dl;c1.setSuit(p1->getSuit();c3.value=12;p1->value=5;c1.print();c2.print();c3.print();*p1.print();cout<<endl;return 0;修改后代码/card.h#ifndef CARD_H#define CARD_Hclass Cardpublic:Card();Card( int s, int v);Card();void setSuit( int s);void setValue( int v);int getSuit() const;int getValue() co

38、nst;void print() const;private:int suit;int value;bool validCard() const;#endif/card.cpp#include <iostream>#include "card.h"using namespace std;Card:Card() suit=4; value=1;Card:Card(int s, int v) suit=s; value=v;Card:Card() cout<< "The destructor has been invokedn"voi

39、d Card:setSuit(int s) suit=s;void Card:setValue( int v) value=v; void Card:print() constif (!validCard() ) cout << "This card is not validn"return;cout<<"This is the: "switch(value)case 1: cout <<"Ace "break;case 11:cout<<"Jack "break;c

40、ase 12:cout<<"Queen "break;case 13:cout << "King "break;default:cout<<value<<" "switch(suit) case 1:cout <<"of clubsn"break;case 2:cout<<"of diamondsn"break;case 3:cout<<"of heartsn"break;case 4:cou

41、t<<"of spadesn"break;default:cout<<"ninvalid suitn"bool Card:validCard() constreturn value>=1 && value <=13 && suit >=1 && suit <=4;int Card:getSuit()const return suit;int Card:getValue()const return value;/debugging.cpp#include <

42、;iostream>#include "card.h"using namespace std;int main()Card c1, c2(3, 4), c3(1, 14);Card *p1=&c2;c1.print();c2.print();c3.print();p1->print();cout<<endl;c1.setSuit(p1->getSuit();c3.setValue(12);p1->setValue(5);c1.print();c2.print();c3.print();p1->print();cout<

43、<endl;return 0; 运行结果4编程题 题目：创建一个SavingAccount类，依据下列要求完成该类的定义。 使用一个static数据成员annualInterestRate保存每个存款者的年利率。 类的每个对象都包含一个private数据成员savingsBalance，用以指示存款者目前的存款金额。 该类提供成员函数calculateMonthlyInterest，它将余额乘以annualInterestRate再除以12来计算月利息，这个利息应该加到savingsBalance中。 该类还提供一个static成员函数modifyInterestRate，它将stati

44、c的annualInterestRate设置为一个新值。 编写一段程序代码测试SavingAccount类。实例化SavingAccount类的两个对象saver1和saver2，余额分别是2000.00元和3000.00元。将annualInterestRate设置为3%，然后计算月利率并打印每个存款者的新余额。接着再将annualInterestRate设置为4%，计算下一个月的利息并打印每个存款者的新余额。要求：根据题目要求，写出类和应用程序的设计思路和程序代码。 思路： 类设计： 应用程序设计：（主函数中，定义对象及调用对象的成员函数）程序代码：/SavingAccount.hclass SavingAccountpublic:SavingAccount(double);SavingAccount();void calculateMonthlyInterest();void printBalance(); static void modifyInterestRate(double );p