Solved

C++ using iomanip

Posted on 2014-02-08
3
450 Views
Last Modified: 2014-02-11
I have the following program in C++ and I need to display the cents part of the amount only. I cannot seem to get it to work using iomanip.

#include <iostream>
#include <iomanip>

using namespace std;

int main ()
{
      
      cout << setiosflags(ios::fixed|ios::showpoint|ios::right);
      
      int quarters, dimes, nickels, pennies;
      float amount;


      cout << "How many quarters? " << endl;
      cin >> quarters;

      cout << "How many dimes? " << endl;
      cin >> dimes;

      cout << "How many nickels? " << endl;
      cin >> nickels;

      cout << "How many pennies? " << endl;
      cin >> pennies;

      amount = (quarters*.25) + (dimes*.10) + (nickels*.05) + (pennies*.01) ;

      cout << "You have " << setprecision(2) << amount << " much money " << endl;

      cout << "You have " << noshowpoint << setprecision(0) << amount << " dollars" << endl;

      cout << "You have " << noshowpoint << setprecision(2) << amount << " cents" << endl;




      return 0;
0
Comment
Question by:CJBOO
3 Comments
 
LVL 31

Assisted Solution

by:Zoppo
Zoppo earned 125 total points
ID: 39846668
Hi CJBOO,

I don't think it's possible to format the output using <iomanip> on cout, for floating point values IMO the number before the decimal point can't be completely supressed. So I think the only possibility you have is to calculate the value for cents, i.e. like this:
 cout << "You have " << (int)( 100.0 * ( 0.005 + amount ) ) % 100 << " cents" << endl;

Open in new window

Here I added 0.005 to the calculated value to avoid rounging errors (i.e. without this the resulting int for 1.52 would be 51).

Hope this helps,

ZOPPO
0
 
LVL 32

Expert Comment

by:phoffric
ID: 39846709
std::ios_base::precision -
•Using the default floating-point notation, the precision field specifies the maximum number of meaningful digits to display in total counting both those before and those after the decimal point. Notice that it is not a minimum, and therefore it does not pad the displayed number with trailing zeros if the number can be displayed with less digits than the precision.
•In both the fixed and scientific notations, the precision field specifies exactly how many digits to display after the decimal point, even if this includes trailing decimal zeros. The digits before the decimal point are not relevant for the precision in this case.
http://www.cplusplus.com/reference/ios/ios_base/precision/

You may wish to review modf:
http://www.cplusplus.com/reference/cmath/modf/
In their example, their output is: 3.141593 = 3.000000 + 0.141593
You know how to handle the whole number. For the decimal part, you would use a method similar to zoppos approach.
0
 
LVL 33

Accepted Solution

by:
sarabande earned 125 total points
ID: 39847225
to add to above comments:

it probably is easiest to have two integer variables dollars and cents and do the rounding as Zoppo has shown by cast from double to int.:

int dollars = (int)amount;
int cents = (int)((amount - dollars+0.005)*100);
std::cout << "You have " << dollars << " dollars" << std::endl;
std::cout << "You have " << cents<< " cents" << std::endl;

Open in new window


Sara
0

Featured Post

Master Your Team's Linux and Cloud Stack!

The average business loses $13.5M per year to ineffective training (per 1,000 employees). Keep ahead of the competition and combine in-person quality with online cost and flexibility by training with Linux Academy.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

A long time ago (May 2011), I have written an article showing you how to create a DLL using Visual Studio 2005 to be hosted in SQL Server 2005. That was valid at that time and it is still valid if you are still using these versions. You can still re…
Entering time in Microsoft Access can be difficult. An input mask often bothers users more than helping them and won't catch all typing errors. This article shows how to create a textbox for 24-hour time input with full validation politely catching …
This is Part 3 in a 3-part series on Experts Exchange to discuss error handling in VBA code written for Excel. Part 1 of this series discussed basic error handling code using VBA. http://www.experts-exchange.com/videos/1478/Excel-Error-Handlin…
This video shows how to quickly and easily add an email signature for all users on Exchange 2016. The resulting signature is applied on a server level by Exchange Online. The email signature template has been downloaded from: www.mail-signatures…

770 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question