Question

美国主要州际公路的编号为1-99。奇数（例如5或95）往北/南，偶数（例如10或90）往东/西。辅助高速公路的编号为100-999，服务于最右边两位数字指示的主要高速公路。因此，405服务于5，而290服务于90。

编写（定义）一个名为printHighwayInfo的公共静态方法，该方法将高速公路编号作为唯一参数（参数将为int）。调用此方法时，应打印出一个String，指示高速公路是主要公路还是辅助公路，以及高速公路是东西向还是南北向（请参见下面的示例）。此方法应具有return void返回类型。

示例：给定公路号，指示它是主要公路还是辅助公路。如果有辅助功能，请指明其服务的主要公路。还要指出（主要）高速公路是北/南还是东/西。

printHighwayInfo（90）将打印90，是主要的，向东/向西移动。 printHighwayInfo（290）将打印290是辅助数据，服务于90，向东/向西移动。 printHighwayInfo（185）将打印185是辅助数据，服务于85，向南/向南移动。您可能希望编写一些其他代码来测试您的方法

提示：

您可以使用模数运算符（％）计算整数除法运算的提示。

例如：290％100将得出90，因为290除以100后的余数为90。

另一个例子：185％2为1，因为2进入185，共92次，剩下1个。另外，请注意，对于任何整数x，当x为奇数时，x％2始终为1，而当x为偶数时它将始终为0。

**这是我使用Java的第一周。到目前为止，我们一直在学习python，而我却遇到了最困难的时刻。我收到大量错误，不知道为什么。我的课堂笔记和讲座根本没有帮助。

    import java.util.Scanner;
public class Main {
  static Scanner scnr = new Scanner(System.in);
}
   public static void main(String[] args) {
        Scanner scnr = new Scanner(System.in);
        int highwayNumber;
        int primaryNumber;
       {
    public static int printHighwayInfo(int a);
    }
        if (printHighwayInfo >= 1 && highwayNumber <= 999) {
            if (printHighwayInfo <= 99) {
                if (printHighwayInfo % 2 == 0) {
                    System.out.println(printHighwayInfo + " is a primary highway, going east/west");
                } else {
                    System.out.println(printHighwayInfo + " is a primary highway, going north/south");
                }
            } else {
                primaryNumber = highwayNumber;
                highwayNumber %= 100;
                System.out.println(printHighwayInfo + " is an auxiliary highway, serving primary highway " + highwayNumber);
            }
        } else {
            System.out.println(printHighwayInfo + " is not a valid interstate highway number.");
        }
    }
}
{
System.out.println(printHighwayInfo(90));           
System.out.println(printHighwayInfo(290));  
System.out.println(printHighwayInfo(185));
}
}

//这些是我回来的错误

HighwayInfo.java:5: error: class, interface, or enum expected
   public static void main(String[] args) {
                 ^
HighwayInfo.java:7: error: class, interface, or enum expected
        int highwayNumber;
        ^
HighwayInfo.java:8: error: class, interface, or enum expected
        int primaryNumber;
        ^
HighwayInfo.java:9: error: class, interface, or enum expected
       {
       ^
HighwayInfo.java:10: error: class, interface, or enum expected
    public static int printHighwayInfo(int a);
                  ^
HighwayInfo.java:11: error: class, interface, or enum expected
    }
    ^
HighwayInfo.java:16: error: class, interface, or enum expected
                } else {
                ^
HighwayInfo.java:18: error: class, interface, or enum expected
                }
                ^
HighwayInfo.java:21: error: class, interface, or enum expected
                highwayNumber %= 100;
                ^
HighwayInfo.java:22: error: class, interface, or enum expected
                System.out.println(printHighwayInfo + " is an auxiliary highway, serving primary highway " + highwayNumber);
                ^
HighwayInfo.java:23: error: class, interface, or enum expected
            }
            ^
HighwayInfo.java:26: error: class, interface, or enum expected
        }
        ^
HighwayInfo.java:31: error: class, interface, or enum expected
System.out.println(printHighwayInfo(290));  
^
HighwayInfo.java:32: error: class, interface, or enum expected
System.out.println(printHighwayInfo(185));
^
HighwayInfo.java:33: error: class, interface, or enum expected
}
^
15 errors

Answer 1

您需要在代码中进行多项更改。

所有方法都应在Main类内部。
没有使用扫描仪，所以将其删除。
方法printHighwayInfo应该具有void返回类型。
方法printHighwayInfo只有一种返回类型，因此应使用一个变量。
需要删除不必要的括号。

我在逻辑上不正确，只是通过消除编译问题来帮助您进一步进行。此外，您可以使用逻辑。

public class Main {

  public static void main(final String[] args) {

    printHighwayInfo(90);
    printHighwayInfo(290);
    printHighwayInfo(185);
  }

  public static void printHighwayInfo(final int highwayNumber) {

    if (highwayNumber >= 1 && highwayNumber <= 999) {
      if (highwayNumber <= 99) {
        if (highwayNumber % 2 == 0) {
          System.out.println(highwayNumber + " is a primary highway, going east/west");
        } else {
          System.out.println(highwayNumber + " is a primary highway, going north/south");
        }
      } else {
        System.out.println(highwayNumber + " is an auxiliary highway, serving primary highway " + highwayNumber);
      }
    } else {
      System.out.println(highwayNumber + " is not a valid interstate highway number.");
    }
  }
}

州际公路（Java）

1 个答案: