Java 编程帮助，适用于 2 个具有控制类的文件

Question

第一个java类是调用其他类的主要类。 我将复制这两个文件的代码。 我无法编译此代码，也不知道为什么。

当我将程序放在一个文件中时，它运行良好，但讲师希望它在两个文件中。 有人可以向我解释我在做什么，或者做错了什么吗？

文件 1：

public class Wk2ToddFoughty {        
    public static void main(String[] args) {
        SalaryCalc FinalSalaryCalc = new SalaryCalc();            
        FinalSalaryCalc.SalaryCalc();               
    }
}

文件 2：

import java.util.Scanner;
class SalaryCalc {                                  
      Scanner in = new Scanner(System.in);
      System.out.println("Enter your annual sales: $");          
      double sales = in.nextDouble();
      double salary = 35000.00;
      double commission = (sales * .015);
      double totalSalary = salary + sales;
      System.out.println("Your Salary + Commission is: $" + totalSalary );   
}

Answer 1

如果您遵守 Java 命名约定，可能会更容易理解 - 另请参阅内联注释

public class Wk2ToddFoughty {        
    public static void main(String[] args) {
        SalaryCalc myCalc = new SalaryCalc();  //  SalaryCalc - name of class
                                               // myCalc - name of object            
        myCalc.doCalc();                       // doCalc - name of method (missing from your class)           
    }
}
// edit this class to add missing method
public class SalaryCalc {                                  
      public void doCalc () {
        Scanner in = new Scanner(System.in);
        System.out.println("Enter your annual sales: $");          
        double sales = in.nextDouble();
        double salary = 35000.00;
        double commission = (sales * .015);
        double totalSalary = salary + sales;
        System.out.println("Your Salary + Commission is: $" + totalSalary );   
    }
}

Answer 2

您的第二个文件没有定义名为 SalaryCalc 的方法。您还应该遵循标准的 Java 命名实践，并将输入/输出逻辑保留在业务类之外。

import java.util.Scanner;
public class Wk2ToddFoughty {        
    public static void main(String[] args) {  
        Scanner in = new Scanner(System.in);
        System.out.println("Enter your annual sales: $");   
        SalaryCalc calc = new SalaryCalc(35000);
        double totalSalary = calc.calcSalary(in.nextDouble());    
        System.out.println("Your Salary + Commission is: $" + totalSalary);
    }
}

---

public class SalaryCalc {
    private double salary;
    public SalaryCalc(double salary) {
        this.salary = salary;
    }
    public void calcSalary(double sales) {
        double commission = sales * 0.015;
        return salary + sales + commission;
    } 
}