我的 java 程序没有输出它应该输出的所有内容。没有错误

Question

我的代码需要一个输入（首先选择颜色，然后是数量）；询问我是否想再做一次（如果是，则重复输入颜色和数量的过程）；然后它将这些值传递给两个不同的方法，这些方法计算每种颜色的价格，然后将计算出的金额返回给 main。

问题是当输入第二种颜色时（在询问“你想再购买一次吗？”之后），它只输出第二种输入的计算价格，而不是第一种。

这是我的代码：

import java.util.Scanner;

public static void main (String[] args)
{
    Scanner in = new Scanner(System.in);

    String answer, color;
    int red_gallons=0;
    int red_gallons_2=0;
    int green_gallons_2=0;
    int green_gallons=0;
    double green_cost=0;
    double red_cost=0;
    System.out.println("which paint color do you wish to purchase (g or r)");  
    color = in.next();

    switch (color)
    {
        case"G":
        case "g":
        {
            System.out.println("how many full gallons of paint do you need");           
            green_gallons = in.nextInt();
            break;
        }
        case"R":
        case "r":
        {
            System.out.println("how many full gallons of paint do you need");           
            red_gallons = in.nextInt();
            break;
        }

    }
    System.out.println("Would you like to make another purchase? (y/n)");
    answer = in.next();

    if (answer.equalsIgnoreCase("Y"))
    {
        System.out.println("which paint color do you wish to purchase (g or r)");   
        color = in.next();
        switch (color)
        {
            case"G":
            case "g":
            {
                System.out.println("how many full gallons of paint do you need");           
                green_gallons_2 = in.nextInt();
                break;
            }
            case"R":
            case "r":
            {
                System.out.println("how many full gallons of paint do you need");           
                red_gallons_2 = in.nextInt();
                break;
            }

        }
    }
    else
    {
        System.out.print("");
    }
    if (color.equalsIgnoreCase("g"))
    {
        green_cost = green_paint(green_gallons,green_gallons_2);
    }
    else if (color.equalsIgnoreCase("r"))
    {
        red_cost = red_paint(red_gallons,red_gallons_2);
    }
    else
    {
        System.out.print("");
    }

    double total_cost = total_bill(red_cost, green_cost);
    String store = store_title();
    thank_you(store, red_cost, green_cost, total_cost ); //BILL

}

//calculates cost of red paint an returns it to main
public static double red_paint(int r_amount_1, int r_amount_2 )
{
    double cost_of_red = 21.95;
    double total_red = cost_of_red*(r_amount_1+r_amount_2);             
    return total_red;                                   
}

//calculates cost of green paint and returns it to main
public static double green_paint(int g_amount_1, int g_amount_2)
{
    double cost_of_green = 19.95;
    double total_green = cost_of_green*(g_amount_1+g_amount_2); 
    return total_green;                         
}

//title of store, returned to main
public static String store_title()
{
    String str = "\n\n*******************\n*THE RAINBOW STORE*\n*******************";
    return str;
}

//calculates bill with tax, and returns it to main  
public static double total_bill(double red$, double green$) 
{
    double bill = red$+green$;              
    double plus_tax = bill+(bill*.08);      
    return plus_tax;                        
}

//prints the bill
public static void thank_you(String stor, double red, double green, double total) 
{
    System.out.println(stor);
    System.out.printf("Red Paint: $%.2f",red);      System.out.println();
    System.out.printf("Green Paint: $%.2f",green);  System.out.println();
    System.out.printf("Total: $%.2f",total);        System.out.println();

    System.out.println("Thank You for shopping at the Rainbow Store!");

}       

Answer 1

if (color.equalsIgnoreCase("g"))
{
    green_cost = green_paint(green_gallons,green_gallons_2);
}
else if (color.equalsIgnoreCase("r"))
{
    red_cost = red_paint(red_gallons,red_gallons_2);
}
else
{
    System.out.print("");
}

这里的ifs 是问题所在。计算不应该是有条件的。