學校作業多維陣列故障

Question

我目前正在爲我的Java編程課程進行作業。我似乎讓自己陷入了一絲困境。任何幫助我意識到我做錯了什麼的幫助將不勝感激。

分配

編寫一個程序，執行以下操作：

把下面的數據到一個多維數組

提示爲公司，他們希望員工工資統計數據的用戶。

編寫一個方法，將平均員工工資作爲雙倍返回。將公司編號和員工工資傳遞給此方法。

編寫一個方法，以int形式返回員工總工資。將公司編號和員工工資傳遞給此方法。

編寫一個方法，以int形式返回僱員數。將公司編號和員工工資傳遞給此方法。

在主要方法中調用其他方法並輸出結果。

請記住，我還是一個新手，並努力去理解編程的一些原理。

當我跑我得到的位置，而不是方法計算程序（壞輸出）：

這是我到目前爲止有：

package salaries; 

import java.util.Scanner; 

public class Salaries { 

    /** 
    * @param args the command line arguments 
    */ 
    public static void main(String[] args) { 

     //declare, instantiate, and define value of multi array [3] [12] 
     double [][] mSalary = { { 49920, 50831, 39430, 54697, 41751, 36110, 
           41928, 48460, 39714, 49271, 51713, 38903}, 
          { 45519, 47373, 36824, 51229, 36966, 40332, 
           53294, 44907, 36050, 51574, 39758, 53847}, 
          { 54619, 48339, 44260, 44390, 39732, 44073, 
           53308, 35459, 52448, 38364, 39990, 47373}}; 

     //declare, instantiate, and define value 
     //of single array for company names 
     //and output values to user for selection 
     String [] company = { "Alhermit", "Logway", "Felter" }; 
     for(int i = 0; i < company.length; i++) 
      System.out.println("Company " + i + " : " +company[i]); 

     Scanner scan = new Scanner(System.in); 
     int cCompany; 
     do{ 
      //ouput for user to select a company 
      System.out.print("Select company: (0)" +company[0]+ ", (1)" 
          +company[1]+ "; (2)" +company[2]+ " > "); 
      //scan user input into cCompany 
      cCompany = scan.nextInt(); 


      //call number method 
      num nums = new num(); 
      nums.number(mSalary, cCompany); 

      //call total method 
      total sum = new total(); 
      sum.total(mSalary, cCompany); 

      //call average method 
      avg cAvg = new avg(); 
      cAvg.average(mSalary, cCompany); 


      //output statistics to user on selected company 
      System.out.println("You have selected the company " + company[cCompany] + ". "); 
      System.out.println(company[cCompany] + " has " + nums + " of employees."); 
      System.out.println("A total employee salary of " + sum + "."); 
      System.out.println("The average employee salary is " + cAvg); 
     } 
      while(cCompany < 0 || cCompany > 2); 
    } 
} 

//total class to calculate 
//salary of user selected company 
class total { 

    public static int total(double [][] mSalary, int cCompany){ 

     //assign variables 
     int sum = 0; 

     //for loop to calculate salary total of user input company 
     for(int j = 0; j < mSalary[cCompany].length; j++){ 
      sum += mSalary[cCompany][j]; 

     } 

    //return statement 
    return sum; 
    } 
} 

//average class to calculate 
//average of user selected company 
class avg { 

    public static double average(double [][] mSalary, int cCompany){ 

     //assign variables 
     int cAvg = 0; 
     int sum = 0; 
     int count = 0; 

     //totals the values for the selected company by 
     //iterating through the array with count. 
     while(count < mSalary[cCompany].length){ 
      sum += mSalary[cCompany][count]; 
      count +=1; 
     } 

      cAvg = sum/mSalary[cCompany].length; 
      return cAvg; 
    } 
} 
//number class to calculate amount of 
//employees in user selected company 
class num { 

    public static int number(double [][] mSalary, int cCompany){ 

     //assign variables 
     int nums = 0; 

     //number of employees based on length of colomn 
     nums = mSalary[cCompany].length; 
     return nums; 
    } 
} 

Answer 1

nums，sum，和cAvg都是你有的類的實例，你打印出這些類的實例。

（順便說一句 - 你應該改變這些類的名稱類別以大寫字母開頭這是它們與變量。）

有兩件事情錯。

1. 您實例包含沒有數據並沒有toString方法的類。
2. 您正在實例化一個只有靜態方法來返回數據的類。你不需要在全部實例化類;相反，只需打印方法調用的結果即可。

這將這些電話中的至少一個更改爲類似：

System.out.println(company[cCompany] + " has " + num.number(mSalary, cCompany); + " of employees."); 

我離開其餘作爲練習留給讀者。