Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

C++ using iomanip

Posted on 2014-02-08
3
Medium Priority
?
495 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 500 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 35

Accepted Solution

by:
sarabande earned 500 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

NFR key for Veeam Backup for Microsoft Office 365

Veeam is happy to provide a free NFR license (for 1 year, up to 10 users). This license allows for the non‑production use of Veeam Backup for Microsoft Office 365 in your home lab without any feature limitations.

Question has a verified solution.

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

This article describes relatively difficult and non-obvious issues that are likely to arise when creating COM class in Visual Studio and deploying it by professional MSI-authoring tools. It is assumed that the reader is already familiar with the cla…
In real business world data are crucial and sometimes data are shared among different information systems. Hence, an agreeable file transfer protocol need to be established.
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…
Is your data getting by on basic protection measures? In today’s climate of debilitating malware and ransomware—like WannaCry—that may not be enough. You need to establish more than basics, like a recovery plan that protects both data and endpoints.…

927 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