c++ taking input in float and converting into string

Question

I want to take float input from user with only two decimal point(999.99) and convert it into string

float amount;
cout << "Please enter the amount:";
cin.ignore();
cin >> amount;
string Price = std::to_string(amount);

my output for this code is 999.989990

Answer 1

to_string doesn't let you specify how many decimal places to format. I/O streams do:

#include <sstream>
#include <iomanip>

std::stringstream ss;
ss << std::fixed << std::setprecision(2) << amount;
std::string Price = ss.str();

If you need to represent the decimal value exactly, then you can't use a binary float type. Perhaps you might multiply by 100, representing prices as an exact integer number of pennies.

Answer 2

If you want to round the number to two decimal digits, you could try:

amount = roundf(amount * 100) / 100;

And then convert it into std::string .