Question

我有一个文本文件（Items.txt），其中包含以下数据：日期，名称，描述和价格，其格式如下：

31/10/2018, Food, Hamburger, 10.00
31/10/2018, Clothes, Hoodie, 50.00
1/11/2018, Games, Controller, 150.00
1/11/2018, Food, Chips, 5.00

我如何只获取食物的总量？这是我到目前为止工作过的片段：

public static double totalFoodExpense(byte choiceCode, byte[] expenseChoiceCode, double[]totalExpense) throws  IOException{
    double total =0;
    double amount = 0;
    String expense= "";
    xpenseCode = 0;
    Scanner kb = new Scanner(System.in);
    Scanner read = new Scanner(new File("Items.txt"));
    System.out.println("Enter the expense code to determine the total amount that you have spent on");
    System.out.println("Codes <  Food(1), Clothes(2), Games(3),  > \n Please " +
            "just enter a number");
    xpenseCode = Byte.parseByte(kb.nextLine());
    while (read.hasNextLine()){
        String oneLine = read.nextLine();
        String[] parts = oneLine.split(",");
        if(xpenseCode == 1){
           //Nothing yet

        }
    }

    return total;
}

用户将输入一个数字（食物1，衣服2，游戏3）确定该商品的总金额。因此，预期的输出将如下所示：

Enter the expense code to determine the total amount that you have spent on
Codes <  Food(1), Clothes(2), Games(3), > Please just enter a number: 
1 <--user input 
The total expense of Food is 15.00

Answer 1

我知道了。

public static double totalTuitionExpense() throws  IOException{
    double total =0;
    double amount = 0;
    String expense= "";
    byte xpenseCode = 0;
    Scanner kb = new Scanner(System.in);
    Scanner read = new Scanner(new File("items.txt"));

    System.out.print("Enter 1 for Food: ");
    try{
    xpenseCode = Byte.parseByte(kb.nextLine());
    double sum = 0.0;
    while (read.hasNextLine()){
        String oneLine = read.nextLine();
        String[] parts = oneLine.split(",");
        amount = Double.parseDouble(parts[3]);
        expense = parts[1];
        if(xpenseCode == 1){
                if (expense.compareToIgnoreCase("tuition")==0) {
                    sum += amount;
                }
            }
        }
    System.out.printf("The total expense of Food is %.2f%n", sum);}
    catch (ArrayIndexOutOfBoundsException e){
        System.out.println("Error");
    }
        return total;
    }

如何使用数组获取文本文件中的某些数据？

1 个答案: