1、實驗二： Classes: A Deeper Look, Part 2實驗目的1掌握類的定義和操作（包括常成員函數）2掌握對常量對象的訪問3掌握使用友元訪問對象的私有數據成員4掌握靜態數據成員和成員函數實驗作業作業一（習題 10.7，Date 類）1. 問題描述( 英文 ) Modify class Date in Fig.10.10 to have the followingcapabilities:a.Output the date in multiple formats such asb.DDD YYYYc.MM/DD/YYd.June 14, 1992e.Use overloaded

2、constructorsto createDate objectsinitializeddates of the formats in part (a).withf. Create a Date constructor that reads the system date using thestandard library functions of the <ctime> header and sets the Date members.(中文 )用下列條件生成Date 類：a)用多種格式輸出日期，例如：DDD YYYY （YYYY 年的第 DDD 天） MM/DD/YYJunel

3、 4,l 992b)用重載的構造函數生成Date 對象，用a)中的日期格式初始化。c)生成一個 Date 構造函數，用 <ctime>頭文件的標準庫函數讀取系統日期和設置 Date 成員。d) 測試各個成員函數2. 實驗提示1）類定義示例：#ifndef DATE_H#define DATE_H#include <string>using std:string;class Datepublic:Date(); / default constructor uses <ctime> functions to set date Date( int, int );

4、/ constructor using ddd yyyy formatDate( int, int, int ); / constructor using dd/mm/yy formatDate( string, int, int ); / constructor using Month dd, yyyy formatvoid setDay( int ); / set the dayvoid setMonth( int ); / set the monthvoid print() const; / print date in month/day/year format void printDD

5、DYYYY() const; / print date in ddd yyyy format void printMMDDYY() const; / print date in mm/dd/yy formatvoid printMonthDDYYYY() const; / print date in Month dd, yyyy format Date(); / provided to confirm destruction orderprivate:int month; / 1-12 (January-December)int day; / 1-31 based on monthint ye

6、ar; / any year;#endif2） 使用 <ctime>頭文件讀取系統日期示例（要求自學該內容）：#include <ctime>using std:time;using std:localtime;using std:tm;using std:time_t;Date:Date()struct tm *ptr;time_t t = time( 0 );ptr = localtime( &t );day = ptr->tm_mday;month = 1 + ptr->tm_mon;year = ptr->tm_year + 1900;

7、3）測試函數要求測試出各種情況。4. 結果示例作業二（習題 10.8，SavingAccount類）1. 問題描述2. 類定義參考#ifndef SAVINGS_ACCOUNT_H #define SAVINGS_ACCOUNT_H class SavingsAccountpublic:/ constructor sets balance to value greater than or equal to zero SavingsAccount( double b )savingsBalance = ( b >= 0.0 ? b : 0.0 ); / end SavingsAccount

8、 constructorvoid calculateMonthlyInterest(); / calculate interest; add to balance static void modifyInterestRate( double );void printBalance() const;private:double savingsBalance; / the account balancestatic double annualInterestRate; / the interest rate of all accounts; / end class SavingsAccount#e

9、ndif3. 結果輸出示例作業三（習題 10.9，IntegerSet 類）1問題描述2 類定義參考#ifndef INTEGER_SET_H#define INTEGER_SET_Hclass IntegerSetpublic:/ default constructor IntegerSet()emptySet(); / set all elements of set to 0 / end IntegerSet constructorIntegerSet( int , int ); / constructor that takes an initial setIntegerSet union

10、OfSets( const IntegerSet& );IntegerSet intersectionOfSets( const IntegerSet& );void emptySet(); / set all elements of set to 0void inputSet(); / read values from uservoid insertElement( int );void deleteElement( int );void printSet() const;bool isEqualTo( const IntegerSet& ) const;privat

11、e:int set 101 ; / range of 0 - 100/ determines a valid entry to the set int validEntry( int x ) constreturn ( x >= 0 && x <= 100 ); / end function validEntry; / end class IntegerSet#endif3結果輸出示例作業四（習題 10.10， Time 類）1問題描述圖 10.1810.19 的 Time 類可以在內部將時間表示為從午夜算起的秒數而不是三個整數值 hour， minute 和 se

12、cond。客戶可以用相同的 public 方法并取得相同結果。修改 Time 類、將時間表示為從午夜算起的秒數，讓類的客戶看不到功能性的變化。2 類定義參考#ifndef TIME_H #define TIME_H class Timepublic:Time( int = 0, int = 0, int = 0 ); / default constructor/ set functions (the Time & return types enable cascading) Time &setTime( int, int, int ); / set hour, minute,

13、second Time &setHour( int ); / set hourTime &setMinute( int ); / set minute Time &setSecond( int ); / set second/ get functions (normally declared const)int getHour() const; / return hourint getMinute() const; / return minuteint getSecond() const; / return second/ print functions (normal

14、ly declared const)void printUniversal() const; / print universal timevoid printStandard() const; / print standard timeprivate:int totalSeconds; / number of seconds since midnight; / end class Time#endif3. 測試函數示例 int main()Time t;t.setHour( 18 ).setMinute( 30 ).setSecond( 22 );/ output time in universal and standard formats cout << "Universal time: " t.pri