C++ 站在双打四舍五入

Question

In c++, std::stod( string ) converts a string to a floating decimals. So, doing this

std::cout << std::stod("378760.58") << "\n";

I would expect it to print 378760.58 to stdout but it rounds up and prints 378761 instead. std::stod() sometimes works as expected but it sometimes acts weird in an unexpected way.

Can anyone explain why and what alternative I could use to convert from string to double in c++? thanks for all the responses:)

Answer 1

you can add "iomanip" head file and use the following code:

std::cout << std::fixed << std::setprecision(2) << std::stod("378760.58") << "\n";