Question

我是一名相当新的Java程序员，目前正在学习如何在一个代码中合并多个方法。此练习活动的目标是使用几种不同的方法：

创建两个阵列（一个用于员工姓名，另一个用于员工销售的数量）

- 找出总销售额的平均值

- 找出最高销售数量

- 找出销售额最高的员工的姓名（打印＆＃34;万岁＆＃34;对于销售额最高的每位员工）

import java.util.*;

public class MethodActivity{

 public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String[] names={"Employee A", "Employee B", "Employee C", "Employee D", "Employee E", "Employee F", "Employee G", "Employee H", "Employee I", "Employee J"};
    System.out.print("Enter the sales numbers, in dollars,  for each employee: ");
    int num1 = sc.nextInt();
    int num2 = sc.nextInt();
    int num3 = sc.nextInt();
    int num4 = sc.nextInt();
    int num5 = sc.nextInt();
    int num6 = sc.nextInt();
    int num7 = sc.nextInt();
    int num8 = sc.nextInt();
    int num9 = sc.nextInt();
    int num10 = sc.nextInt();
    double[] sales={num1, num2, num3, num4, num5, num6, num7, num8, num9, num10};
    return double[] sales;
    return String[] names;
 }

    public static double getAverage(double[] sales){
        double average=(num1+num2+num3+num4+num5+num6+num7+num8+num9+num10)/10;
        return average;
   }
    public static int getHighestSale(double[] sales){
        double highest = sales[0];
        int locationOfHighest=0;
        if(sales[1]>highest){
            highest=sales[1];
            locationOfHighest=1;
        }else if(sales[2]>highest){
            highest=sales[2];
            locationOfHighest=2;
        }else if(sales[3]>highest){
            highest=sales[3];
            locationOfHighest=3;
        }else if(sales[4]>highest){
            highest=sales[4];
            locationOfHighest=4;
        }else if(sales[5]>highest){
            highest=sales[5];
            locationOfHighest=5;
        }else if(sales[6]>highest){
            highest=sales[6];
            locationOfHighest=6;
        }else if(sales[7]>highest){
            highest=sales[7];
            locationOfHighest=7;
        }else if(sales[8]>highest){
            highest=sales[8];
            locationOfHighest=8;
        }else{
            highest=sales[9];
            locationOfHighest=9;
        }
        return highest;
    }
    public static String showName(String[] names){
        String nameOfHighest = "";
        String hooray = "";
        for (int i = 0; i<names.length; i++){
            if (i=locationOfHighest){
                nameOfHighest=nameOfHighest+names[i]+", ";
                hooray = ""+"hooray ";
            }else{
                nameOfHighest=nameOfHighest;
            }
        }
        return nameOfHighest;
    }

 public static void (String[] args){
    System.out.println("The average sales for today was: "+average);
    System.out.println(nameOfHighest+" made the highest sales of "+highest);
    System.out.println(hooray);
 }
}

然而，当我运行程序时，我遇到了这些错误。问题是，我真的不明白他们的意思：

MethodActivity.java:20: error: '.class' expected
            return double[] sales;
                            ^

MethodActivity.java:21: error: '.class' expected
            return String[] names;
                            ^

MethodActivity.java:75: error: <identifier> expected
    public static void (String[] args){

如果有人能澄清这些意思，我真的很感激，因为我仍然对多方法代码的概念感到困惑。并且，如果可以的话，也许可以在我的代码中指出任何其他问题或可修复的元素（因为我知道我的代码对于有编程经验的人来说看起来很邋and，我真的可以使用一些指针）。感谢您的时间。

Answer 1

你需要删除这两个回报。您的代码中存在两个问题：

1）java方法只能有一个return语句。

2）它是主要方法，因为它返回void类型。 void表示没有返回类型。

Answer 2

而是使用单独的方法来打印“public static void（String [] args），在main方法本身中打印它们。另请参阅iMBMT的回答。

Answer 3

import java.util.Scanner;

public class MethodActivity {

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter Number of employees : ");
    int totalEmployeeCount = sc.nextInt();
    System.out.println("## totalEmployeeCount : " + totalEmployeeCount);
    String[] employeeNames = new String[totalEmployeeCount];
    int[] employeeSoldCount = new int[totalEmployeeCount];
    String name;
    int count;
    for (int index = 0; index < totalEmployeeCount; index++) {
        System.out.print("Enter employee name : ");
        name = sc.next();
        System.out.print("Enter employee sale count : ");
        count = sc.nextInt();
        employeeNames[index] = name;
        employeeSoldCount[index] = count;
    }

    System.out.println("---------------- Pringting all info ----------------");

    for (int i = 0; i < employeeNames.length; i++) {
        System.out.println("name : " + employeeNames[i] + " & sale count : " + employeeSoldCount[i]);
    }

    findTheAverageOfTotalSales(employeeSoldCount);
    findTheHighestSaleNumber(employeeSoldCount);

}

private static void findTheAverageOfTotalSales(int[] employeeSoldCount) {
    for (int saleCount : employeeSoldCount) {
        System.out.println("Write your own code ...");
    }
}

private static void findTheHighestSaleNumber(int[] employeeSoldCount) {
    for (int saleCount : employeeSoldCount) {
        System.out.println("Write your own code ...");
    }
}

}

Answer 4

你需要学习更多，你的代码语法和逻辑有几个问题试着使用for loop获取输入：

int nums=new int[10];
for(int i=0;i<10;i++){
  nums[i]=sc.nextInt();
}

不要在void方法return中使用(used in main method)语句，除非您想要退出，但有更好的退出方式。
在return声明中，您不需要指定返回类型(used at the end of main method) ，这是在方法定义中完成的：
正确的回报和方法定义：

public static String[] myMethod(){
   String [] strings={"one","two"};
   return strings;
}

寻找最高销售额使用循环：

public int indexOfHighestSale(double[] sales){
    int highest=0;
    int index=0;
    for(int i=0;i<sales.length;i++){
        if(sales[i]>highest){
           highest=sales[i];
           index=i;
        }
    }
    return index;
}

您的上一个方法需要一个名称（标识符）和一些更正：

public static void print(String average,String nameOfBestSeller
                        ,double highestSale,String hooray){

    System.out.println("The average sales for today was: "+average);
    System.out.println(nameOfHighest+" made the highest sales of "+highest);
    System.out.println(hooray);
}

并且main方法应该按顺序调用方法并传递正确的参数：

public static void main(String [] args){
     Scanner sc = new Scanner(System.in);
     String[] names={"Employee A", "Employee B", "Employee C", "Employee D", "Employee E", "Employee F", "Employee G", "Employee H", "Employee I", "Employee J"};
     System.out.print("Enter the sales numbers, in dollars,  for each 
     employee: ");
     int [] sales =new int[10];
     for(int i=0;i<10;i++){
         sales[i]= sc.nextInt();    
     }
     double average=getAverage(sales);
     int index=indexOfHighestSale(sales);
     print(average,names[index],sales[index],"hooray");
}

在同一代码上使用多个方法遇到的问题

4 个答案: