Question

Hello stackoverflow社区。目前我是java的新手，我正在试图弄清楚如何编写模块程序。无论出于何种原因，当我返回变量averageScore时，它会在main方法中为该变量提供错误。任何帮助将不胜感激。

public class Program4
{

public static void main(String[  ] args)
{
    EasyReader console = new EasyReader(); //Connect to EasyReader.class
    System.out.print("Enter the score from game 1: ");
    double score1 = console.readDouble(); //Reads the user input for game 1 
    System.out.print("Enter the score from game 2: ");
    double score2 = console.readDouble(); //Reads the user input for game 2
    System.out.print("Enter the score from game 3: ");
    double score3 = console.readDouble(); //Reads the user input for game 3
    average(score1, score2, score3);
    displayScores(score1, score2, score3, averageScore);
}
public static void average(double score1, double score2, double score3)
{
    double averageScore = ((double)score1+score2+score3)/3; //Divides miles by gallons  
    getAverage();
}
public static double getAverage()
{
    return new averageScore;
}   
public static void displayScores(double score1, double score2, double score3, double averageScore)
{
    System.out.println("Game 1 Score: " + score1 + " points"); //Prints score 1
    System.out.println("Game 2 Score: " + score2 + " points"); //Prints score 2
    System.out.println("Game 3 Score: " + score3 + " points"); //Prints score 3     
    System.out.println("Average score: " + RoundDouble.roundDouble(averageScore, 2) + " points "); //Prints the average score and rounds it to 2 decimals
}
}

Answer 1

试试这个：

public static double average(double score1, double score2, double score3)
{
    return ((double)score1+score2+score3)/3; //Divides miles by gallons  
}

然后在你的main方法中，你可以这样做：

EasyReader console = new EasyReader(); //Connect to EasyReader.class
System.out.print("Enter the score from game 1: ");
double score1 = console.readDouble(); //Reads the user input for game 1 
System.out.print("Enter the score from game 2: ");
double score2 = console.readDouble(); //Reads the user input for game 2
System.out.print("Enter the score from game 3: ");
double score3 = console.readDouble(); //Reads the user input for game 3
double averageScore = average(score1, score2, score3);
displayScores(score1, score2, score3, averageScore);

您不再需要getAverage（）方法

Answer 2

您的变量score1，score2，score3，averageScores都是方法内的本地变量。将它们声明为attributes的{{1}}，然后通过class Program4 instantiating的对象访问它们。

Answer 3

这里有一些问题：

average(score1, score2, score3);

您尚未将返回值分配给本地可访问的任何内容。例如，将average()的值分配给局部变量，就像使用score3一样。

public static void average(double score1, double score2, double score3)
{
    double averageScore = ((double)score1+score2+score3)/3; //Divides miles by gallons  
    getAverage();
}

什么？只需从此处返回averageScore，无需再调用其他方法。

从单独的方法返回变量，但我仍然会收到错误

3 个答案: