precision of fixed in c++

The std::fixed manipulator in C++ is used to set the floating-point output format to fixed-point notation. It specifies that the floating-point values should be displayed with a fixed number of digits after the decimal point.

To use std::fixed, you need to include the <iomanip> header file. This header provides the necessary functions and manipulators for working with input/output operations in C++.

Here are the steps to set the precision of std::fixed in C++:

1. Include the <iomanip> header file at the beginning of your program:

#include <iomanip>

1. Declare and initialize your floating-point value:

double number = 3.14159265358979323846;

1. Use the std::fixed manipulator to set the floating-point output format to fixed-point notation:

std::cout << std::fixed;

1. Set the desired precision for the fixed-point notation. This specifies the number of digits to be displayed after the decimal point:

std::cout << std::setprecision(2);

In this example, 2 is used as the precision value, which means that the output will display two digits after the decimal point.

1. Output the value using the std::cout statement:

std::cout << number << std::endl;

The output will now display the floating-point value number in fixed-point notation with the specified precision.

Here's a complete example:

#include <iostream>
#include <iomanip>

int main() {
    double number = 3.14159265358979323846;
    std::cout << std::fixed;
    std::cout << std::setprecision(2);
    std::cout << number << std::endl;
    return 0;
}

Output:

3.14

This example demonstrates how to use std::fixed and std::setprecision to set the precision of fixed-point notation in C++.