java - Getter 和 Setter 函数帮助和操作方法

Question

我目前正在编写一个程序，需要在其中合并 get 函数来为程序生成和输出。该计划需要座位数 A = 30，每个座位 A 的价格 = 120.99。我认为我的程序设置方式我需要做的就是调用这些函数，然后设置金额，然后打印。我尝试过使用 ConcertSales ConcertSales= new ConcertSales();但每当我准备调用该函数时，我都会使用 ConcertSales.getNumberOfSeatsTypeA();或 ConcertSales.setNumberOfSeatsTypeA(30) ，它给了我一条错误消息。我究竟做错了什么？请帮忙!这是我的代码:

public static void main(String[] args) {
class ConcertSales{
ConcertSales concertSales = new ConcertSales();
public int numberOfSeatTypesA;
public int numberOfSeatTypesB;
public double pricePerSeatA;
public double pricePerSeatB;
public double totalSales; 

public int getNumberOfSeatTypesA()
{ return numberOfSeatTypesA;}
//did the same for Types B

public void setNumberOfSeatTypesA(int newValue) 
 { numberOfSeatTypesA = newValue; }
//same done for SeatsB

public double computeTotalSales()
{ return totalSales = numberOfSeatTypesA*pricePerSeatA +
                       numberOfSeatTypesB*pricePerSeatB }
}
concertSales.setNumberOfSeatTypesA(30); //this is where i keep getting 
my error messages. 

感谢任何帮助!谢谢您

Answer 1

我认为你是一个Java初学者，或者是一个OOP初学者。在Java中，所有函数/方法都应该在类的内部，甚至是main函数。

这是代码:

class ConcertSales{
    public int numberOfSeatTypesA;
    public int numberOfSeatTypesB;
    public double pricePerSeatA;
    public double pricePerSeatB;
    public double totalSales; 

    public int getNumberOfSeatTypesA(){ 
        return numberOfSeatTypesA;
    }

    public void setNumberOfSeatTypesA(int newValue){ 
        numberOfSeatTypesA = newValue; 
    }

    public double computeTotalSales(){ 
        return totalSales = numberOfSeatTypesA*pricePerSeatA +
                   numberOfSeatTypesB*pricePerSeatB;
    }

    public static void main(String[] args) {
        ConcertSales concertSales = new ConcertSales();
        concertSales.setNumberOfSeatTypesA(30); 
        System.out.println(concertSales.getNumberOfSeatTypesA());
    }
}