java - 编译Java代码时找不到符号

This question already has answers here:

What does a “Cannot find symbol” or “Cannot resolve symbol” error mean?

(15个答案)

3年前关闭。

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进行编译时，都会出现14种类型的错误:**error: cannot find symbol。例如:

Exercise1.java82: error: cannot find symbol else if(flag==true).

符号^也在f下方。

最佳答案

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

例如

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

也

在YearDays中，您正在尝试访问flag变量，该变量不是字段，并且不会作为参数传递，因此请尝试

称呼为

YearDays(year2, flag);

并将方法更改为

private int YearDays(int y, boolean flag){

看起来您也需要对MonthDays执行此操作

关于java - 编译Java代码时找不到符号，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40901309/

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