Java 将考试成绩写入文件

Question

我需要让用户循环输入10个分数并将每个分数写入文件“scores.txt”，但程序在我输入一个分数后终止。我不确定如何让程序将 10 个乐谱中的每一个都写入文件。

最终程序应提示用户输入多个分数，将分数写入文件，然后打开该文件，计算平均值并显示。

循环的退出条件可以是负分；如果是否定的，我可以假设用户已完成输入数据。

public class MoreTestScores {

/**
 * @param args the command line arguments
 */

public static void main(String[] args) throws IOException {
    writeToFile("scores.txt");
    processFile("scores.txt");
}

public static void writeToFile (String filename) throws IOException {
    BufferedWriter outputWriter = new BufferedWriter(new FileWriter("scores.txt"));
    System.out.println("Please enter 10 scores.");
    System.out.println("You must hit enter after you enter each score.");
    Scanner sc = new Scanner(System.in);
    int score = 0;
    while (score <= 10)
    {
        score = sc.nextInt();
        outputWriter.write(score); }
}

public static void processFile (String filename) throws IOException, FileNotFoundException {
    double sum = 0;
    double number;
    double average;
    double count = 0;
    BufferedReader inputReader = new BufferedReader (new InputStreamReader(new FileInputStream("scores.txt")));
    String line;
    while ((line = inputReader.readLine()) != null) {
        number = Double.parseDouble(line);
        sum += number;
        count ++; }
    average = sum/count;
    System.out.println(average);
    inputReader.close();
}

Answer 1

你应该使用 counter跟踪输入:

int count = 0;
int score = 0;
while (count < 10) {
  score = sc.nextInt();
  if(score < 0) break;
  outputWriter.write(score);
  count++;
}

你在做什么:

int score = 0;
while (score <= 10) {
  score = sc.nextInt();
  outputWriter.write(score);
}

每当您输入大于 10 的值时(我假设你是你的第一个输入)，循环将终止为条件 score <= 10变成 false .