float roundoff(float value, unsigned char prec) { float pow_10 = pow(10.0f, (float)prec); return round(value * pow_10) / pow_10; } auto rounded = roundoff(100.123456, 3); // rounded = 100.123;
value = round( value * 100.0 ) / 100.0; // 2 decimal places value = round( value * 1000.0 ) / 1000.0; // 3 decimal places
double d = 0.12345; std::cout.precision(2); // for accuracy to 2 decimal places std::cout << d << std::endl; // 0.12