Question

我有一个程序可以计算用户输入的日期是否为闰年。我想我已经完成了所有这一切，但我还需要看看输入的日期是否是二进制日期（即1/1/11。我不确定最好的方法去做这个，也许是一个charAt参考？任何帮助都必须得到赞赏！

//****************************
import java.util.Scanner;

public class leapYearCalc {
private int day = 0;
private int month = 0;
private int year = 0;
Scanner myScan = new Scanner (System.in);


//---------------------------------
//Constructor to accept and initialize instance data
//---------------------------------
public leapYearCalc(int day, int month, int year){
this.day=day;
this.month=month;
this.year=year;
}

//--------------------------------
//Get day
//--------------------------------
public int getDay(){
    System.out.println("Whats the day?");
    day = myScan.nextInt();
    return day;
}

//--------------------------------
//Get day
//--------------------------------
public int getMonth(){
    System.out.println("Whats the month in numerical form?");
    month = myScan.nextInt();
    return month;
}

//--------------------------------
//Get day
//--------------------------------
public int getYear(){
    System.out.println("Whats the year (i.e. 2004)?");
    year = myScan.nextInt();
        if (year<1582)
            System.out.println("Please enter a value above 1582");
    return year;
}


//--------------------------------
 //1. If a year is divisible by 4 it is a leap year if 2 does not apply.
 //2. If a year is divisible by 100 it is not a leap year unless #3 applies.
 //3. If a year is divisible by 400 it is a leap year.
//--------------------------------
//Calculate leap year   
public String toString() {
        if (year % 4 == 0) {
            if (year % 100 != 0) {
            System.out.println(year + " is a leap year.");
            }
            else if (year % 400 == 0) {
            System.out.println(year + " is a leap year.");
            }
            else {
            System.out.println(year + " is not a leap year.");
            }
        }
        else {
            System.out.println(year + " is not a leap year.");
        }
        return null;
    }

    //--------------------------------
    //Check to see if date is binary
    //--------------------------------
    public int getBinary(){
        while(month == 01 || month == 10)

            if(day == 01 || day == 10 && year == 00 || year == 01)
                System.out.println("It's a binary date!");
        System.out.println("It's not a binary date");
        return month;

    }
}

Answer 1

因为这是一个家庭作业，我只会给你提示：我打赌“二元日期”的意思是年，月和日只由“1”和“0”组成？

以下是提示：

使用SimpleDateFormat将提供的Date转换为String。结果应该只包含8个字符：4表示年份，2表示月份，2表示日期
检查结果字符串以查看它是否包含全0或1.您可以使用for循环检查每个字符以查看它们是“0”还是“1”，或者您只需使用正则表达式来检查模式“^ [01] + $”

Answer 2

因此，您要检查日，月和年字段是否为1 10 0r 11.如果它们是二进制日期，否则它不是二进制日期。也许你的getBinary（）方法应该只返回一个布尔值。你不需要在那里使用while循环，而是使用if语句：

public boolean getBinary(){
    if(month == 1 || month == 10 || month == 11){
        if(day == 1 || day == 10 || day = 11){
              if(year == 0 || year == 1 || year == 10 || year == 11){
                 return true;
              }

     }
     return false;
}

此外，如果从可被400整除开始，可以简化闰年计算。例如

  if(year is divisible by 400)
      leap year
  else
      if year is divisible by 100 then
         not a leap year
      else
           if year is divisble by 4 then
              leap year
           else
              not a leap year

或者它都可以变成像这样的简单布尔表达式

 if(year is divisible by 400 or (year is not divisble by 100 and divisible by 4))
        leap year
 else
        not leap year

=================== 考虑到四位数年份，您可以将每个数字分开：

     int num = year; //to preserve the original year value
     int digit = num / 1000; //get first digit
     //check if digit is 0 or 1
     num = num % 1000; //remove first digit
     digit = num / 100; //get second digit
     //check if digit is 0 or 1
     num = num % 100;//remove second digit
     etc

Answer 3

好的我可能为时已晚，但最好的方法是使用正则表达式

   public boolean getBinary(){
        String str = day+""+month+"year";
        return str.matches("[01]+");

    }

java - 确定日期是否为二进制

3 个答案: