浮点值不显示精确的位数c ++

Question

无法为我的$输出提供正确的数字。

每当我在声明中插入例如8时，我会得到3位数的Ex。 10.9 虽然我希望它显示10.90美元

我刚刚添加了setprecision，希望它能解决问题，不起作用

#include <iostream>
#include <iomanip>
using namespace std;


int main()
{
    int Ts;    // holds Ts 
    float Price, Tcost, Total;


    cout << "How many shirts you like ?" << endl;
    cin >> Ts;

    Total = 12 * Ts;

    if ( 5 < Ts && Ts < 10)
        Tcost = (Total - (.10 * Total));
        Price = (Tcost / Ts);
        cout << "he cost per shirt is $" << setprecision(4) << Price << " and the total cost is $" << Tcost << setprecision(4) << endl;




    return 0;


}

Answer 1

使用std::fixed的组合（其将设置由setprecision(N)决定的打印点之后的小数位数）和std::setprecision(2)（因此打印两位小数），并且代码现在应该可以工作：

#include <iostream>
#include <iomanip>
using namespace std;


int main()
{
    int Ts;    // holds Ts 
    float Price, Tcost, Total;


    cout << "How many shirts you like ?" << endl;
    cin >> Ts;

    Total = 12 * Ts;

    if ( 5 < Ts && Ts < 10)
        Tcost = (Total - (.10 * Total));
        Price = (Tcost / Ts); // The indentation is weird here
                              // but I will leave it as it is
        cout << "he cost per shirt is $" << fixed << setprecision(2) << Price << " and the total cost is $" << Tcost << setprecision(2) << endl;
    return 0;


}

我得到的输出是：

How many shirts you like ?
8
he cost per shirt is $10.80 and the total cost is $86.40

Answer 2

你必须写std::cout.setf(std::ios::showpoint);然后才能运作。