Question

我无法弄清楚如何显示一个月而不必在我的开关中显示“1月” - 如果我尝试只是输入它我得到1号

我是否需要为dateDate创建内存;私人会员？比我的拷贝构造函数中的副本？

抱歉格式化。我不得不移动东西，所以它会在这个页面上正确显示

这就是我所拥有的。我是否需要为私人会员日期创建内存？

class date
  {
   public:
typedef enum {INVALID, JANUARY, FEBRUARY, MARCH, APRIL, MAY, JUNE,
              JULY, AUGUST, SEPTEMBER, OCTOBER, NOVEMBER, DECEMBER}
Month;

date(Month month, int day, int year);
date(const date& date);                 // copy constructor
date(void);                             // default constructor
~date(void);

friend ostream& operator<<(ostream& out, const date& d);

    private:
Month   month;
int     day;
int     year;
    };

也

class stock
 {
 public:
stock(char const * const symbol, char const * const name, int sharePrice, date priceDate);
// sharePrice is given as a number of CENTS
stock(const stock& s);                      // copy constructor
stock(void);                                // default constructor
char const * const getSymbol(void) const;
stock& operator=(const stock& s);
stock& operator=(stock const * const s);
~stock(void);

// display column headers
static void displayHeaders(ostream& out);   // display the headers when this instance is printed

// prints share price as DOLLARS
// (e.g. 2483 would print out as 24.83 and 200 would print out as 2.00)
friend ostream& operator<<(ostream& out, const stock& s);

friend class hashmap;


    private:

int  sharePrice;
char* name;
char* symbol;
date priceDate;
int removed;


   };

现在的功能。

date::date(Month month, int day, int year)
 {

this->day = day; 
this->month = month;
this->year = year;



   }

 /**
 * date: copy constructor
 * in: date
 * out: out
 * return: none
 **/

 date::date(const date& date):day(date.day),month(date.month),year(date.year)
 {

  }

  date::date()
  {

day = 0;
year = 0;
month = INVALID;


   }

  date::~date(void)
 {



   }

   ostream& operator<<(ostream& out, const date& d)

{

switch(d.month)
{

case 1: out << "January " << d.day <<", " << d.year;
    break;
case 2: out << "Febuary "<< d.day <<", " << d.year;
    break;
case 3: out << "March "<< d.day <<", " << d.year;
    break;
case 4: out << "April "<< d.day <<", " << d.year;
    break;
case 5: out << "May "<< d.day <<", " << d.year;
    break;
case 6: out << "June "<< d.day <<", " << d.year;
    break;
case 7: out << "July " << d.day <<", " << d.year;
    break;
case 8: out << "august "<< d.day <<", " << d.year;
    break;
case 9: out << "September "<< d.day <<", " << d.year;
    break;
case 10: out << "October "<< d.day <<", " << d.year;
    break;
case 11: out << "November "<< d.day <<", " << d.year;
    break;
case 12: out << "december "<< d.day <<", " << d.year;
    break;
}

return out;
  }

Answer 1

这样的事情：

const char* const MonthNames[] = { "", "January", "February", "March", "April", "May", "June" ... };

out << MonthNames[d.month] << ' ' << d.day << ", " << d.year;

Answer 2

看看strftime。

Answer 3

使用数组和枚举类型。

class date {
public:
  enum Month {
    JAN, FEB, MAR, APR, MAY, JUN,
    JUL, AUG, SEP, OCT, NOV, DEC
  };

  date(int y, Month m, int d) : _y(y), _m(m), _d(d) {}

  int year()    const { return _y; }
  Month month() const { return _m; }
  int day()     const { return _d; }

  const std::string& month_name(Month m) const {
    return months[m];
  }

private:
  int _y;
  Month _m;
  int _d;
  static std::string months[];

  friend std::ostream& operator <<(std::ostream &o, const date &d);
}

不要忘记为date::months和流插入运算符定义存储：

std::string date::months[] = {
  "January", "February", "March", "April", "May", "June",
  "July", "August", "September", "October", "November", "December"
};

std::ostream& operator <<(std::ostream &o, const date &d)
{
  o << d.day()                 << ' '
    << d.month_name(d.month()) << ' '
    << d.year();

  return o;
}

样本用法：

int main()
{
  date d(2009, date::NOV, 21);

  std::cout << d << std::endl;

  return 0;
}

Answer 4

枚举只是数字。如果您希望枚举值与字符串对应，则需要创建某些排序的映射，例如：

const char * asString(Month month)
{
    static const char * cMonths[] = { "January", "February", "March",
                                      "April", "May", "June",
                                      "July", "August", "September",
                                      "October", "November", "December" };
    return cMonths[static_cast<int>(month) - 1];
}

我是否需要为此创建内存私人会员约会？

date priceDate;

此代码没问题。运行时将为您分配堆栈上所需的内存。

显示一个月不是数字1

4 个答案: