java - 为什么编译器会提示 illegal start of expression 错误消息？

Question

此代码会查看多个文件，以查找您输入的任何名称的流行度和含义。有错误的类常量用于我尚未在类中制作的图表。它们现在没有被使用，但很快就会被使用。

我遇到了这些错误:

BabyNames.java:8: error: illegal start of expression
   public static final int STARTINGYEAR = 1890;
   ^
BabyNames.java:8: error: illegal start of expression
   public static final int STARTINGYEAR = 1890;
          ^
BabyNames.java:8: error: ';' expected
   public static final int STARTINGYEAR = 1890;
                ^
BabyNames.java:9: error: illegal start of expression
   public static final int WIDTH = 60;
   ^
BabyNames.java:9: error: illegal start of expression
   public static final int WIDTH = 60;
          ^ 
BabyNames.java:9: error: ';' expected
   public static final int WIDTH = 60;
                ^
BabyNames.java:10: error: illegal start of expression
   public static final int HEIGHT = 30; 
   ^
BabyNames.java:10: error: illegal start of expression
   public static final int HEIGHT = 30; 
          ^
BabyNames.java:10: error: ';' expected
   public static final int HEIGHT = 30;

我想我这里有所有正确的分号，但我不确定发生了什么这是我的代码:

import java.util.*;
import java.io.*;
//import java.lang.*;

public class BabyNames{ //ADD COMMENTS
   public static void main(String[] args) throws FileNotFoundException{
   public static final int STARTINGYEAR = 1890;
   public static final int WIDTH = 60;
   public static final int HEIGHT = 30; 
      Scanner console = new Scanner(System.in);
      DrawingPanel panel = new DrawingPanel(780,560);
      Graphics g = panel.getGraphics();
      Scanner nameFile = new Scanner(new File("names.txt"));
      Scanner meaningsFile = new Scanner(new File("meanings.txt"));
      Scanner nameFile2 = new Scanner(new File("names2.txt"));
      intro();
      //nameToLowerCase(console);
      if(STARTINGYEAR = 1890){
      findingStatistics(console,nameFile);
      }
      else{
      findingStatistics(console, nameFile2);       
      drawGraph(g);
   }



   public static void intro(){
      System.out.println("This program allows you to search through the");
      System.out.println("data from the Social Security Administration");
      System.out.println("to see how popular a particular name has been");
      System.out.println("since 1890" );
      System.out.println();
      System.out.print("Name: ");
      }

   public static String nameToLowerCase(Scanner console, Scanner data){   
      String originalName = console.next();
      String name = "" ;
      int lengthOfName = originalName.length();
      String beginingOfName = originalName.substring(0,1).toUpperCase();
      String endOfName = originalName.substring(1,lengthOfName).toLowerCase();
      name = beginingOfName + endOfName;
      return name;
   }
   public static String findingStatistics(Scanner console, Scanner data){
      String nameFinal = nameToLowerCase(console);
      boolean goesThroughOnce = false; //
      String statistics = "";
      String currWord = "";
      String currLine = "";
      while (data.hasNext() && goesThroughOnce == false){ 
         currLine = data.nextLine();
         Scanner lineBeingRead = new Scanner(currLine); //make other scanners?? for each file
         currWord = lineBeingRead.next(); //

         if (currWord.equals(nameFinal) || currWord.equals(nameFinal.toUpperCase())){   //         
            statistics = currLine;
            goesThroughOnce = true;
            System.out.println(statistics);
        }
        else{
        }
   }
   return statistics;
}

Answer 1

这些在 Java 中称为常量，它们应该在类本身中定义，而不是在其主要方法中定义。

public static final int STARTINGYEAR = 1890;
..... 

现在，如果您删除 public static，您可以将它们保留在您的 main 方法中，但似乎这不是您想要的。此外，这将无法在其他方法中使用它们，因为它们将成为 main 方法的局部最终变量。