小编use*_*427的帖子

我是C++的新手,我想知道如何输出/写入声明为double的变量到txt文件.我知道如何使用fstream输出字符串,但我无法弄清楚如何发送任何其他内容.我开始认为你不能发送任何东西,但字符串到文本文件是正确的吗？如果是这样,那么如何将存储在变量中的信息转换为字符串变量？

这是我的代码,我正在尝试实现这个概念,它相当简单:

int main()
{

double invoiceAmt = 3800.00;
double apr = 18.5;            //percentage

//compute cash discount
double discountRate = 3.0;    //percentage
double discountAmt;

discountAmt = invoiceAmt * discountRate/100;

//compute amount due in 10 days
double amtDueIn10;

amtDueIn10 = invoiceAmt - discountAmt;

//Compute Interest on the loan of amount (with discount)for 20 days
double LoanInt;

LoanInt = amtDueIn10 * (apr /360/100) * 20;

//Compute amount due in 20 days at 18.5%.
double amtDueIn20;

amtDueIn20 = invoiceAmt * (1 + (apr …