Question

import acm.program.*;

public class Exercise1 extends Program{

    public void run(){

     int i;
     for(i=1; i<=2; i++){

         if(i==1){
             int s = readInt("Give a number for the current day, 0:Sunday, 1:Monday, 2:Tuesday, 3:Wednesday, 4:Thursday, 5:Friday, 6:Saturday :");
             String dayName1 = DayName(s);
             int day1 = readInt("Give the number of the current day:");
             int month1 = readInt("Give the number of the current month:");
             int year1 = readInt("Give the current year:");
             boolean flag = LeapYearCheck(year1);
             int yearDays1 = YearDays(year1);
             int monthDays1 = MonthDays(month1);
            }
         else{
             int s = readInt("Give a number for your desired day, 0:Sunday, 1:Monday, 2:Tuesday, 3:Wednesday, 4:Thursday, 5:Friday, 6:Saturday :");
             String dayName2 = DayName(s);
             int day2 = readInt("Give the number of a day of your choice:");
             int month2 = readInt("Give the number of a month of your choice:");
             int year2 = readInt("Give your desired year:");
             boolean flag = LeapYearCheck(year2);
             int yearDays2 = YearDays(year2);
             int monthDays2 = MonthDays(month2);
            }
        }
     if(year1>=year2){
         int sumC = yearDays1 + monthDays1 + day1;
         int sumG = yearDays2 + monthDays2 + day2;
         int sum;
         if( sumG > sumC )
             sum = sumG - sumC;
         else if( sumC > sumG )
             sum = sumC - sumG;
         println("It has been " + sum + " Days since " + day2 + "/" + month2 + "/" + year2 + " " + dayName2);
        }
     else
         println("This date has not come yet.");
    }

    public String DayName(int s){

     switch (s){

         case 0:return("Sunday");
         case 1:return("Monday");
         case 2:return("Tuesday");
         case 3:return("Wednesday");
         case 4:return("Thursday");
         case 5:return("Friday");
         case 6:return("Saturday");
        }
    }

    private boolean LeapYearCheck(int Y){

     boolean flag;
     if(Y/4 == 0 && Y/100 != 0 || Y/400 == 0 && Y/100 !=0)
         return flag = true;
     else
         return flag = false;
    }

    private int YearDays(int y){

         if( flag == true)
             return 366;
         else
             return 365;
        }

    private int MonthDays(int m){

         if( m==1 || m==3 || m==5 || m==7 || m==8 || m==10 || m==12)
             return 31;
         else if(m!=2)
             return 30;
         else if(flag==true)
             return 29;
         else
             return 28;
    }

}

每次尝试在命令行上编译时，我都会得到所有类型的14个错误：**error: cannot find symbol。例如：

Exercise1.java82：错误：如果（flag == true），则无法找到符号。

符号^也位于f。

之下

Answer 1

如果在块中声明变量，例如if(i==1){... int yearDays1然后此变量的可见性仅限于该块。将它们移到run方法的顶部

e.g。

  public void run(){
       int yearDays1 = 0;
       ...

同时

在YearDays中，您正在尝试访问不是字段且未作为参数传递的变量flag，请尝试

呼叫

YearDays(year2, flag);

并将方法更改为

private int YearDays(int y, boolean flag){

看起来您需要为MonthDays
执行此操作

编译Java代码时找不到符号

1 个答案: