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C++ Data Types

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Arithmetic Operations

Setting the precision

As you already should know you can perform basic data manipulation using arithmetic operators such as addition (+), subtraction (-), division (/), and multiplication (*). Additionally, the modulus operator (%) calculates the remainder of a division.

cpp

main

copy
#include <iostream>
#include <iomanip>

int main()
{
// Uncomment to see the difference
// std::cout << std::fixed;
std::cout << std::setprecision(5) << 15.125 * 0.8309 << std::endl;
}

              
123456789

            
#include <iostream>
#include <iomanip>

int main()
{
    // Uncomment to see the difference
    // std::cout << std::fixed;
    std::cout << std::setprecision(5) << 15.125 * 0.8309 << std::endl;
}

In the example above, floating-point results may occasionally be produced during calculations. To manage the precision of these results, you can use std::setprecision in combination with std::fixed. This allows you to control the number of digits displayed after the decimal point, ensuring consistent precision in your output.

Note

Without std::fixed, std::setprecision controls the total number of digits displayed, including both before and after the decimal points. With std::fixed, the number is displayed in fixed-point notation, keeping the decimal point in a fixed position.

Uppgift

Swipe to start coding

  1. Include <iomanip> to be able to set precision.
  2. Follow the comments to set a precision.
  3. Calculate and output the equivalent of 5 miles in kilometers rounding to one decimal place.

Note

To convert 5 miles to kilometers, you would multiply the number of miles by the conversion factor (1.60934).

Lösning

cpp

solution

#include <iostream>
#include <iomanip>
int main()
{
// Use std::fixed to set precision for digits only after the decimal
// To set the precision to the 1 you have to use std::setprecision(1)
// Make sure to add it after std::cout << and before expression
std::cout << std::fixed << std::setprecision(1) << 5 * 1.60934 << std::endl;
}
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Avsnitt 1. Kapitel 2
#include <iostream>
#include <___>

int main()
{
// Use std::fixed to set precision for digits only after the decimal
// To set the precision to the 1 you have to use std::setprecision(1)
// Make sure to add it after std::cout << and before expression
std::cout << ___ << ___(_) << 5 * ___ << std::endl;
}

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