c++ - 似乎无法精确排列小数

Question

我有一个简单的程序，它询问电影的名称，以及 set1 和 set2 的售票数量。然后它对这些值进行一些计算并显示结果。我遇到的唯一问题是我似乎无法按照我希望的方式排列十进制值。

控制台中的最后三行输出应始终如下所示(美元符号和小数点对齐):image .但是当我为 set1 门票输入 1，为 set2 门票输入 0 时，反之亦然，它看起来像这样:image .关于如何使输出始终像第一个屏幕截图那样很好地排列的任何想法？提前致谢。

    #include <iostream>
    #include <string>
    #include <iomanip>

    using namespace std;

    int main() {

    string film = "";

    int set1 = 0;
    int set2 = 0;
    // the cinema always takes this 20% cut.
    const double CINEMA_FEE = 0.20;
    double profit = 0;
    double profitMinusFee = 0;
    double paidToMovieMaker = 0;

    cout << "What is the name of the film: ";
    getline(cin, film);

    cout << "How many tickets for set1 sold: ";
    cin >> set1;

    cout << "How many tickets for set2 sold: ";
    cin >> set2;

    cout << "Film Name:" << setw(20) << "\"" << film << "\"" << endl;
    cout << "Set1 tickets sold:" << setw(16) << set1 << endl;
    cout << "Set2 tickets sold:" << setw(16) << set2 << endl;

    set1 *= 10;
    set2 *= 6;
    profit = set1 + set2;
    profitMinusFee = profit * CINEMA_FEE;
    paidToMovieMaker = profit - profitMinusFee;
    // needs to always show two decimal points and fixed
    cout << setprecision(2) << fixed;
    cout << "The total monetary profit:" << setw(5) << "$ " << profit << endl;
    cout << "The net monetary profit:" << setw(7) << "$ " << profitMinusFee << endl;
    cout << "Total paid to movie maker:" << setw(5) << "$ " << paidToMovieMaker << endl;

    return 0;
    }

Answer 1

我认为您的问题是您在美元符号而不是数字上设置宽度。

这似乎为我解决了这个问题:

#include <iostream>
#include <string>
#include <iomanip>

using namespace std;

int main() {

    string film = "";

    int set1 = 0;
    int set2 = 0;
    // the cinema always takes this 20% cut.
    const double CINEMA_FEE = 0.20;
    double profit = 0;
    double profitMinusFee = 0;
    double paidToMovieMaker = 0;

    cout << "What is the name of the film: ";
    getline(cin, film);

    cout << "How many tickets for set1 sold: ";
    cin >> set1;

    cout << "How many tickets for set2 sold: ";
    cin >> set2;

    cout << "Film Name:" << setw(20) << "\"" << film << "\"" << endl;
    cout << "Set1 tickets sold:" << setw(16) << set1 << endl;
    cout << "Set2 tickets sold:" << setw(16) << set2 << endl;

    set1 *= 10;
    set2 *= 6;
    profit = set1 + set2;
    profitMinusFee = profit * CINEMA_FEE;
    paidToMovieMaker = profit - profitMinusFee;
    // needs to always show two decimal points and fixed
    cout << setprecision(2) << fixed;
    cout << "The total monetary profit: $ " << setw(10) << profit << endl;
    cout << "The net monetary profit  : $ " << setw(10) << profitMinusFee << endl;
    cout << "Total paid to movie maker: $ " << setw(10) << paidToMovieMaker << endl;

    return 0;
}

记住 setw() 会影响 它之后的东西。