A problem with setprecision

[Nille]

Ok ive got a bit of a problem with setprecision.

I have made a program that outputs a bunch of numbers all ending with 2 decimals (using setprecision(2)) and then it saves it in a .txt file but instead of saving 2 decimals it writes stuff like 8e+004.

can i not use setprecision when im writing to a file or am i just doing it the wrong way?

plz help //Nille.

[v0id]

I think you've maybe misunderstood what std::setprecision is doing. You aren't setting the precision for the decimals, but for the whole... "number."

#include <iostream>
#include <iomanip>

int main()
{
	double fNumber = 12.34;
	
	std::cout << std::setprecision(1) << fNumber << std::endl; // 1e+001
	std::cout << std::setprecision(2) << fNumber << std::endl; // 12
	std::cout << std::setprecision(3) << fNumber << std::endl; // 12.3
	std::cout << std::setprecision(4) << fNumber << std::endl; // 12.34
	
	return 0;
}