set precision on floating numbers

#include <iostream>
#include <iomanip>

int main() {
    double number = 3.14159;

    // Set precision to 3 decimal places
    std::cout << std::fixed << std::setprecision(3) << number << std::endl;

    return 0;
}

Explanation:

• #include <iostream>: Includes the input/output stream for handling input and output operations.
• #include <iomanip>: Includes the input/output manipulator for controlling output formatting.
• double number = 3.14159;: Declares a double variable named number and assigns the value 3.14159.
• std::cout << std::fixed << std::setprecision(3) << number << std::endl;: Prints the value of number to the standard output (std::cout) with a precision of 3 decimal places. std::fixed ensures that floating-point numbers are displayed in fixed-point notation.
• std::setprecision(3): Sets the precision of floating-point output to 3 decimal places.

This code will output 3.142, rounding the original number 3.14159 to three decimal places.