round up to n decimal places c++ code example

Example 1: how to print a decimal number upto 6 places of decimal in c++

#include <iostream>
#include <iomanip>

int main()
{
    double d = 122.345;

    std::cout << std::fixed;
    std::cout << std::setprecision(2);
    std::cout << d;
}

Example 2: round double to n decimal places c++

value = round( value * 100.0 ) / 100.0; // 2 decimal places
value = round( value * 1000.0 ) / 1000.0; // 3 decimal places