Question

我正在为我的编程课编写这段代码，我可以完成所有其他工作，但是我的输出格式对我来说却行不通。

#include <iostream>
#include <iomanip>
#include <ios>

    using namespace std;

    int main()
    {
        double tip_fifteen;
        double tip_twenty;
        double tax;
        double bill;
        char dollars = '$';
        float meal_cost;

        cout << "Enter the meal cost: ";
        cin >> meal_cost;
        tip_twenty = meal_cost * .20;
        tip_fifteen = meal_cost * .15;
        tax = meal_cost * 0.0975;
        cout << "******************************************" << endl;

        //beginning outputs
        int digits;
        digits = meal_cost * 100 / 100;
        cout << setw(10) << left << "Meal Cost " << dollars;
        cout << setw(to_string(digits).length() + 3) << fixed << showpoint << setprecision(2) << meal_cost << endl;

        cout << setw(10) << left << "Tax " << dollars;
        cout << setw(to_string(digits).length() + 3) << fixed << showpoint << setprecision(2) << tax << endl;

        cout << setw(10) << left << "Tip (15%) " << dollars;
        cout << setw(to_string(digits).length() + 3) << fixed << showpoint << setprecision(2) << tip_fifteen << endl;

        //tip outputs then final output statements
        cout << setw(10) << left << fixed << setprecision(2) << "Tip (20%) " << dollars << tip_twenty << endl;
        bill = tip_fifteen + meal_cost + tax;
        cout << "Your total bill is " << fixed << setprecision(2) << dollars << bill << " after 15% gratuity." << endl << "or" << endl;
        bill = tip_twenty + meal_cost + tax;
        cout << "Your total bill is " << fixed << setprecision(2) << dollars << bill << " after 20% gratuity." << endl;



return 0;

我希望我的输出看起来像这样

Enter the meal cost: 56
******************************************
Meal Cost $ 56.00
Tax       $  5.46
Tip (15%) $  8.40
Tip (20%) $ 11.20
Your total bill is 69.86 after 15% gratuity.
or
Your total bill is 72.66 after 20% gratuity.

我的输出看起来像这样

Enter the meal cost: 56
******************************************
Meal Cost $56.00
Tax       $5.46 
Tip (15%) $8.40 
Tip (20%) $11.20
Your total bill is $69.86 after 15% gratuity.
or
Your total bill is $72.66 after 20% gratuity.

我在使用setw和float时遇到问题，但是当我尝试将相同的变量设置为int时，它不起作用。我也尝试过使用setw（25）来查看它是否可以正常工作，不幸的是，

Answer 1

如果要使它们向右对齐，则需要使用right，还需要在dollars

后添加一个空格“”。

cout << setw(10) << left << "Meal Cost " << dollars << " ";
cout << setw(to_string(digits).length() + 3) << fixed << right << showpoint << setprecision(2) << meal_cost << endl;

对于所有已打印的报表，您将得到：

******************************************
Meal Cost $ 56.00
Tax       $  5.46
Tip (15%) $  8.40
Tip (20%) $ 11.20

Answer 2

要在价格列中添加填充，必须将setw设置为足够大的宽度。

例如：

std::cout << "$" << std::setw(10) << std::fixed
          << std::setprecision(2) << 56.0f << std::endl;

打印：

$     56.00

您的代码将宽度设置为：

std::to_string(digits).length() + 3

只有5个字符，正好适合“ 56.00”。对于左侧的其他填充，您应该增加setw的宽度。

背诵和提示输出对齐C ++，输出格式

2 个答案: