c++ - 使用 Math::Round

Question

我有以下可视化 C++ 代码

#include <iostream>
#include <string>
#include <sstream>
#include <math.h>

using namespace std;

int Main()
{
    double investment = 0.0;
    double newAmount = 0.0;
    double interest = 0.0;
    double totalSavings = 0.0;
    int month = 1;
    double interestRate = 0.065;

    cout << "Month\tInvestment\tNew Amount\tInterest\tTotal Savings";
    while (month < 10)
    {
            investment = investment + 50.0;
        if ((month % 3 == 0))
        {
          interest = Math::Round((investment * Math::Round(interestRate/4, 2)), 2);
        }
        else
        {
          interest = 0;
        }
        newAmount = investment + interest;
        totalSavings = newAmount;
        cout << month << "\t" << investment << "\t\t" << newAmount << "\t\t" << interest << "\t\t" << totalSavings;
        month++;
    }
  string mystr = 0;
  getline (cin,mystr);
  return 0;
}

但是它给我带来了使用 Math::Round 的问题，我真的不知道如何使用 visual c++ 使用这个函数

Answer 1

Math::Round() 是 .NET，而不是 C++。

我不相信 C++ 中有直接相等的东西。

你可以这样写你自己的(未经测试):

double round(double value, int digits)
{
  return floor(value * pow(10, digits) + 0.5) / pow(10, digits);
}