Question

该程序应该返回

考试成绩按降序排列是：（分数）平均值是（平均）

我收到的结果是

平均分为（平均）测试分数按降序排列：（分数）

如何解决它以获得适当的回报

//Check whether the device has a fingerprint sensor//
    if (!mFingerprintManager.isHardwareDetected()) {
        // If a fingerprint sensor isn’t available, then inform the user that they’ll be unable to use your app’s fingerprint functionality//
        textView.setText("Your device doesn't support fingerprint authentication");
    }
    //Check whether the user has granted your app the USE_FINGERPRINT permission//
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.USE_FINGERPRINT) != PackageManager.PERMISSION_GRANTED) {
        // If your app doesn't have this permission, then display the following text//
        Toast.makeText(EnterPinActivity.this, "Please enable the fingerprint permission", Toast.LENGTH_LONG).show();
    }

    //Check that the user has registered at least one fingerprint//
    if (!mFingerprintManager.hasEnrolledFingerprints()) {
        // If the user hasn’t configured any fingerprints, then display the following message//
        Toast.makeText(EnterPinActivity.this, "No fingerprint configured. Please register at least one fingerprint in your device's Settings", Toast.LENGTH_LONG).show();
    }

    //Check that the lockscreen is secured//
    if (!mKeyguardManager.isKeyguardSecure()) {
        // If the user hasn’t secured their lockscreen with a PIN password or pattern, then display the following text//
        Toast.makeText(EnterPinActivity.this, "Please enable lockscreen security in your device's Settings", Toast.LENGTH_LONG).show();
    }

要完成这项工作，我需要交换些什么？

编辑：此文件中使用了平均值类

import java.util.Scanner;

public class Average
{
    private int[] data;
    private double mean;

    public Average()
    {
        data = new int[5];
        int number = 0;
        int Temp = 0;
        String[] Scores = new String[5];
        Scanner keyboard = new Scanner(System.in);

        for(int index = 0; index < data.length; index++)
        {
            number++;
            System.out.print("Enter test score #" + number + ":");
            Temp = keyboard.nextInt();
            data[index] = Temp;
        }

        selectionSort();
        calculateMean();
    }

    public void selectionSort()
    {
        int n = data.length;

        for(int index = 0; index < n-1; index++)
        {
            int min_idx = index;
            for(int j = index+1; j < n; j++)
                if(data[j] >= data[min_idx])
                    min_idx = j;

            int temp = data[min_idx];
            data[min_idx] = data[index];
            data[index] = temp;
        }
    }

    public String toString()
    {
        String MyScore = "Your test scores in descending order are: " +     "\n";

        for(int index = 0; index < data.length; index++)
        {
            MyScore += data[index] + " ";
        }
        return MyScore;
    }

    public void calculateMean()
    {
        int Sum = 0;
        int Mean = 0;

        for(int index = 0; index < data.length; index++)
        {
            Sum += data[index];
        }
        Mean = Sum/data.length;
        System.out.println("The average is " + mean);
    }
}

Answer 1

仅应在致电calculateMean()后致电toString()。
因此，您可以修改构造函数

selectionSort();
System.out.println(toString());
calculateMean();

或仅在构造函数中调用selectionSort();，然后在您的main

中调用

public class AverageDriver
{
    public static void main(String[] args)
    {
         Average myScores = new Average();
         System.out.print(myScores);
         myScores.calculateMean();
    }
}

顺便说一句，您应该为变量使用小写名称，这将解决calculateMean()中的错误：您正在调用System.out.println("The average is " + mean);，但变量为Mean。

Answer 2

无法打印正确平均值的错误在于此方法：

您要打印出public void calculateMean() { int Sum = 0; int Mean = 0; for (int index = 0; index < data.length; index++) { Sum += data[index]; } Mean = Sum / data.length; System.out.println("The average is " + mean); }，它是全局定义的，但从未初始化，因此默认为mean。在此方法中，您拥有变量0（大写），它是实际值存储在其中的变量，即您要打印的变量。

Answer 3

public static void main(String[] args)
{
    Average MyScores = new Average();
    System.out.print(MyScores);
}

创建Average实例时，将调用构造函数。在构造函数中，有一个对calculateMean()的调用，它会打印

平均值是（平均值）

当您打印MyScores时，将调用覆盖toString()，并进行打印。测试分数按降序排列：（分数）。

从构造函数中取出方法调用（它们不应该放在首位），然后从main调用它们

public static void main(String[] args)
{
    Average myScores = new Average();
    System.out.print(myScores);
    myScores.selectionSort();
    myScores.calculateMean();
}

如何修复脚本以正确的顺序运行？

3 个答案: