Question

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

int main ()
{
//Declare variables
    double pounds, grams, kilograms;
//Declare constants
    const double LB2GRM = 453.592;
//Give title to program
    cout << "Pound to kilograms converter" << endl;
//Prompt the user to enter a weight
    cout << "Please enter a weight in pounds: " << endl;
    cin >> pounds;
//Displaying weight with two decimal points
    cout << setiosflags(ios::showpoint) << setprecision(2);
//Round off weight
    static_cast<double>(static_cast<double>(pounds +.5));
//Formula for conerversion
    double fmod(pounds * LB2GRM);
    cin >> grams;
//Show results
    cout << pounds << " pounds are equal to " << kilograms << " kgs and " << grams << " grams" << endl;

return 0;
}

如何将克转换成千克？我找到了第一部分，只是不确定如何完成它？我只需输入千克常数吗？

Answer 1

在打印之前，您永远不会向kilograms分配任何内容。你应该从公式中指定它。

grams = pounds * LB2GRM;
// Divide grams by 1000 to get the kg part
kilograms = floor(grams / 1000));
// The remaining grams are the modulus of 1000
grams = fmod(grams, 1000.0);

此外，这句话没有做任何事情：

static_cast<double>(static_cast<double>(pounds +.5));

首先，将某些内容转换为相同类型无效。其次，你没有将演员表的结果分配给任何东西（演员没有修改它的参数，它只返回转换后的值）。我怀疑你想要的是：

pounds = static_cast<double>(static_cast<int>(pounds +.5));

但更简单的方法是使用floor()函数：

pounds = floor(pounds + .5);

将double投射到int将删除分数。

如何将磅转换为克和千克 - C ++

1 个答案: