使用Iomanip进行C ++格式化

Question

I am trying to format the output of my code using iomanip:

cout.setf(ios::fixed);
cout.setf(ios::showpoint);
cout.precision(2) << "Modified: resistor "<< rname << " to "<< res << " Ohms"<<endl;

but i recieve an error on the third line:

error: invalid operands of types 'std::streamsize' and 'const char [20]' to binary 'operator<<'|

Answer 1

Use

std::cout << std::setprecision(2) << ... << '\n';

or:

std::cout.precision(2);
std::cout << ... << '\n';

The function ios_base::precision does not return the stream it operates on, so you can't stream anything into it directly.