Question

我试图从输入文件中读取整数＆＃34; input.txt＆＃34;并分隔整数并添加数字。我的这个代码给了我一个错误，说sum的方法是一个非法的开始。有什么指针吗？

public static void main(String[] args){

    //declarations
    boolean fileOpened = true;
    Scanner inputFile = null;
    int sumNum, num;
    //read input
    String fileName = " ";
    System.out.println("Please input the name of the file to be opened: ");
    Scanner input = new Scanner(System.in);
    fileName = input.nextLine();

    try{
        inputFile = new Scanner(new File(fileName));
    }
    catch(FileNotFoundException e){
        System.out.println("--- File NOT Found! ---");
        fileOpened = false;
    }

    if(fileOpened && inputFile.hasNext()){
        sumNum = sum(num);//method call
        while(inputFile.hasNextInt()){
            if(inputFile.hasNextInt()){
                num = inputFile.nextInt();
                System.out.println("For number " + num + " the sum of the digits is: " + sumNum);
            }
            else{
                inputFile.next();
            }
        }
    }

    public static int sum(int num){
        int i, sumNum = 0;
        for(i = 1; i <= num; i++){
            sumNum += num % 10;
            num /= 10;
        }
        return sumNum;
    }
}

Answer 1

您在主要方法中缺少}。您还没有初始化num。

我已修复主要输出正确的输出。你的方法还有其他问题。你在错误的地方调用sum方法。请尝试以下答案：

public static void main(String[] args){
        //declarations
        boolean fileOpened = true;
        Scanner inputFile = null;
        int sumNum, num = 0;
        //read input
        String fileName = "";
        System.out.println("Please input the name of the file to be opened: ");
        Scanner input = new Scanner(System.in);
        fileName = input.nextLine();
        try{
          inputFile = new Scanner(new File(fileName));
        }
        catch(FileNotFoundException e){
          System.out.println("--- File NOT Found! ---");
          fileOpened = false;

        }

          while(inputFile.hasNextInt()){
              num = inputFile.nextInt();
              sumNum = sum(num);//method call
              System.out.println("For number " + num + " the sum of the digits is: " + sumNum);
        }
      }

在输入文件java错误中求和整数的数字

1 个答案: