從年齡

Question

計算出生日期我們如何計算給定年齡的出生日期。例如，如果我的年齡是24歲-02月-02天，那麼我們如何計算出生日期爲1993年3月29日？

Answer 1

Checkout example code for converting age to date of birth.

public abstract class AgeCalculate { 

    protected abstract void getResult(String result); 

    public AgeCalculate() { 
    } 

    public void calculateAGE(Year dateOfBirth, Year ageAtTheDateOf) { 
     if (ageAtTheDateOf.year < dateOfBirth.year) { 
      getResult("dateOfBirth can no be greater than ageAtTheDateOf."); 
     }//Date of birth needs to be earlier than the age at date. 

     long years = ageAtTheDateOf.year - (dateOfBirth.year + 1); 
     long months = years * 12; 
     long days = 0; 


     for (int index = 0; index < years; index++) { 
      int year = dateOfBirth.year + index; 
      if (!isLeapYear(year)) { 
       days += 365; 
      } else { 
       days += 366; 
      } 
     } 

     long monthInclude; 
     if (ageAtTheDateOf.month == 0) { 
      monthInclude = (12 - dateOfBirth.month); 
     } else { 
      monthInclude = (12 - dateOfBirth.month) + (ageAtTheDateOf.month - 1); 
     } 


     long dayInclude = (daysInPriorMonth(dateOfBirth.month, dateOfBirth.year) - dateOfBirth.day) + (ageAtTheDateOf.day); 

     for (int index = 12; index > dateOfBirth.month; index--) { 
      days += daysInPriorMonth(index, dateOfBirth.year); 
     } 

     for (int index = 1; index < ageAtTheDateOf.month; index++) { 
      days += daysInPriorMonth(index, dateOfBirth.year); 
     } 

     days += dayInclude; 

     String age; 
     age = "YOUR AGE IS " + years + " Years " + monthInclude + " Months and " + 
       dayInclude + " Days(" + (daysInPriorMonth(dateOfBirth.month, dateOfBirth.year) - dateOfBirth.day) + " Days of " + dateOfBirth.month + "/" + dateOfBirth.year 
       + " and " + ageAtTheDateOf.day + " Days of " + ageAtTheDateOf.month + "/" + ageAtTheDateOf.year + ")"; 
     age += "\n"; 
     age += "AGE IN DAYS : " + days + " Days."; 
     age += "\n"; 
     age += "AGE IN HOURS : " + (days * 24) + " Hours."; 
     age += "\n"; 
     age += "AGE IN SECONDS : " + ((days * 24) * 60) + " Minutes."; 
     age += "\n"; 
     age += "AGE IN MILLISECONDS : " + (((days * 24) * 60) * 1000) + " Milli Seconds."; 

     getResult(age); 
    } 

    public void calculateDOB(Year date, Year ageAt) { 
     if (!isValidateNumber(date.day, 0, 31, "Day of cal") || 
       !isValidateNumber(date.year, 0, 2999, "Year of cal") || 
       !isValidateNumber(ageAt.year, 0, 1000, "Years aged") || 
       !isValidateNumber(ageAt.month, 0, 11, "Months aged") || 
       !isValidateNumber(ageAt.day, 0, 30, "Days aged")) { 
      return; 
     } 


     Year result2 = diffDateAgeAndOutput(date.year, date.month, date.day, ageAt.year, ageAt.month, ageAt.day, 2); // Borrow from month before death 

     getResult(result2.toString()); 

    } 

    private boolean isValidateNumber(int num, int min, int max, String msg) { 
     if (num < min || max < num) { 
      getResult(msg + " not in range [" + min + "..." + max + "]"); 
      return false; 
     } 
     return true; 
    } 

    private Year diffDateAgeAndOutput(int yd, int md, int dd, int ya, int ma, int da, int method) { 
     int db = dd - da, 
       mb = md - ma, 
       yb = yd - ya; 

     if (db < 1) { 

      switch (method) { 
       case 1: 
        db += 30; 
        break; 

       case 2: 
        db += daysInPriorMonth(md, yd); 

        if (db < 1) { 

         md -= 1; 
         if (md < 0) { 
          md = 11; 
          yd -= 1; 
         } 
         db += daysInPriorMonth(md, yd); 
         mb -= 1; 
        } 
        break; 

       case 3: 
        db += daysInPriorMonth(mb, yb); 
        if (db < 1) { 
         mb -= 1; 
         if (mb < 0) { 
          mb = 11; 
          yd -= 1; 
         } 
         db += daysInPriorMonth(mb, yb); 
        } 
        break; 
      } 
      mb -= 1; 
     } 
     if (mb < 0) { 

      mb += 12; 
      yb -= 1; 
     } 

     return new Year(db, mb, yb); 
    } 

    private boolean isLeapYear(int year) { 
     String x = String.valueOf((double) year/4); 
     return x.contains("."); 
    } 

    private int daysInPriorMonth(int month, int year) { 
     if (month == 1) 
     { 
      return 31; 
     } 

     if (month == 2) 
     { 
      if (isLeapYear(year)) { 
       return 29; 
      } else { 
       return 28; 
      } 
     } 

     if (month == 3) 
     { 
      return 31; 
     } 

     if (month == 4) 
     { 
      return 30; 
     } 

     if (month == 5) 
     { 
      return 31; 
     } 

     if (month == 6) 
     { 
      return 30; 
     } 

     if (month == 7) 
     { 
      return 31; 
     } 

     if (month == 8) 
     { 
      return 31; 
     } 

     if (month == 9) 
     { 
      return 30; 
     } 

     if (month == 10) 
     { 
      return 31; 
     } 

     if (month == 11) 
     { 
      return 30; 
     } 

     if (month == 12) 
     { 
      return 31; 
     } 

     return 0; 
    } 
}