在函数中找不到符号

Question

我正在尝试在函数中获取一些用户输入，但由于某种原因，我的代码无法识别我的输入流。当我去编译时，我在第 81 行收到一个错误，说找不到 reader.readLine（）。有谁知道如何解决这个问题？或者是否有可能让运行函数在初始 do-while 循环中发生而没有任何问题？

import java.io.*;
public class JavaLab3 {

public static void main(String[] args) {
  // first we define our input streams.
  InputStreamReader input = new InputStreamReader(System.in);
  BufferedReader reader = new BufferedReader(input);
  // variable declarations
  String   sName, playAgain;
  // we catch exceptions if some are thrown.
  // an exception would be entering a string when a number is expected
  try {
        System.out.println("what is your name?");
        // we read a string from the stream
        sName = reader.readLine();
        do {
          run();
          System.out.println(sName + "would you like to play again?");
          System.out.println("Please answer in lowercase 'yes' or 'no'.");
          playAgain = reader.readLine();
        } while (playAgain != "no");
  } catch (IOException e){
        System.out.println("Error reading from user");
  }
}
public static int maxRun (int runTotal) {
int highScore = 0;
if (runTotal > highScore) {
  highScore = runTotal;
} else {
  `highScore = highScore`}
 return highScore;
}

public static int run () {
Integer currentRun = 0, uNumber, counter;
final Integer MAX = 4;
final Integer MAX_NUMBER = 100;
//While current total is less than the max
while (currentRun < MAX) {
  System.out.println("Please enter a number.");
  //store user number
  uNumber = Integer.parseInt(reader.readLine());  //Line throwing the error.
  //for each number under 5 repetitions
  for (counter = 0; counter <= MAX_NUMBER ; counter++ ) {
    if (uNumber < 0) {
      System.out.println("Please enter a positive number.");
    } else if ((uNumber % 2) != 0) {
      System.out.println("Please enter an even number.");
    } else {
      //sets current total and restarts the loop
      currentRun = uNumber + currentRun;
    }
  }
}
//Calls maxRun function to see if score the score is the highest.
maxRun(currentRun);
System.out.println("The max for this run was, " + currentRun + ".");
return currentRun;
}

}

Answer 1

reader是在main()方法的范围内定义的。它不存在于run()范围内。

您可以将其定义为类的成员，以便两种方法都可以访问它。或者将其作为方法之间的参数传递。

Answer 2

读取器是在 main 方法内部定义的，其范围在 main 方法内部，要在 run 方法中访问它，您可以在 run（） 方法中传递它，以便它可以在那里使用。

Answer 3

BufferedInput 读取器定义应该在 main 函数外部声明，即在类内部，然后它将是全局的，并且可以通过类的任何方法访问。

Class name {
       buffereInput reader = ....
 .....
 }