New to C++ Problem

Hi,

I've just started to learn C++ and I am having problems with what I thought would be a simple program.
Here is the source code:

#include <iostream>

using namespace std;
int main()
{
float quantity;
float price;
float factor;
float bondCost;
bondCost = ((quantity*price*factor)/100);

cout << "Welcome to the bond calculator." << endl;
cout << "This program only calculates the cost of a bond."<< endl;
cout << "No attempt is made to calcualte the interest." << endl;
cout << "" <<endl;
cout << "Bond Information" <<endl;
cout << "" <<endl;
cout << "Enter the quantity: ";
cin >> quantity;
cout << "Enter the price of the the bond: ";
cin >> price;

cout << "" <<endl;
cout << "The factor must now be calcualted into the principal." <<endl;
cout << "Note that if the bond does not have a factor then enter '1'." << endl;
cout << "" <<endl;
cout << "Enter factor: ";
cin >> factor;

cout << "" <<endl;
cout << "The cost of this bond is: " << bondCost;

return 0;

}

The program is meant to calculate the cost of a bond using the following equation:

quantity * price * factor / 100

an example:

Quantity of bonds to be purchased: 1,000,000
Price of bonds: 105.25
Factor: .08736524
Cost of Bonds would be: 91,951.9151

1,000,000 * 105.25 * .08736524 = 91,951.9151

Unfortunately the program calculates the cost of the bond to be 0



I've also modified the code as follows:

#include <iostream>
#include <string>
using namespace std;
int main()
{
float quantity;
float price;
float factor;



cout << "Welcome to the bond calculator." << endl;
cout << "This program only calculates the cost of a bond."<< endl;
cout << "No attempt is made to calcualte the interest." << endl;
cout << "" <<endl;
cout << "Bond Information" <<endl;
cout << "" <<endl;
cout << "Enter the quantity: ";
cin >> quantity;
cout << "Enter the price of the the bond: ";
cin >> price;

cout << "" <<endl;
cout << "The factor must now be calcualted into the principal." <<endl;
cout << "Note that if the bond does not have a factor then enter '1'." << endl;
cout << "" <<endl;
cout << "Enter factor: ";
cin >> factor;

cout << "" <<endl;
cout << "The cost of this bond is: " << ((quantity*price*factor)/100);

return 0;

}

This sort of works. ussing the same values as the first example I get a cost of 91951.9 (it has rounded the number down - not what I want it to do).

But if I were to enter the following factor in the equation :

.99999999

I get this: 1.0525e+006


What am I doing incorrectly?

Thanks for the help.

Ok, theres 3 problems I can see in your source.

1) In the first case you are calculating bondCost before you assign values to the variables so presumably its initialising the other variables to 0 hence your answer is 0.

2) In both cases you are using floats for your variables and MSVC complained at me when I tried to set a float equal to 0.08736524 saying it was truncating from a double.

3) You need to set the precision for cout to something that will cope with your output. (See the following src).

Hope this helps,

-KM-

#include <iostream>
#include <string>
using namespace std;

int main()
{
double quantity;
double price;
double factor;
double bond_cost;

cout << "Welcome to the bond calculator." << endl;
cout << "This program only calculates the cost of a bond."<< endl;
cout << "No attempt is made to calcualte the interest." << endl;
cout << "" <<endl;
cout << "Bond Information" <<endl;
cout << "" <<endl;
cout << "Enter the quantity: ";
cin >> quantity;
cout << "Enter the price of the the bond: ";
cin >> price;

cout << "" <<endl;
cout << "The factor must now be calcualted into the principal." <<endl;
cout << "Note that if the bond does not have a factor then enter '1'." << endl;
cout << "" <<endl;
cout << "Enter factor: ";
cin >> factor;

cout << "" << endl;

bond_cost = quantity * price * factor / 100;

cout.precision (10);
cout << "The cost of this bond is: " << bond_cost << endl;

return 0;
}

you can also use

cout.setf(ios::showpoint);
cout.precision(2);

to set the precision of the response to two points after the decimal

Thanks,

KM, your suggestion worked.



Drizzle, your suggestion (at least as I have coded it - see below) does not set the prescision to 2 decimal places. The output is still displayed in scientific format.

#include <iostream>
#include <string>
using namespace std;
int main()
{
double quantity;
double price;
double factor;
double bondCost;


cout << "Welcome to the bond calculator." << endl;
cout << "This program only calculates the principal of a bond."<< endl;
cout << "No attempt is made to calcualte the interest." << endl;
cout << "" <<endl;
cout << "Bond Information" <<endl;
cout << "" <<endl;
cout << "Enter the quantity: ";
cin >> quantity;
cout << "Enter the price of the the bond: ";
cin >> price;

cout << "" <<endl;
cout << "The factor must now be calcualted into the principal." <<endl;
cout << "Note that if the bond does not have a factor then enter '1'." << endl;
cout << "" <<endl;
cout << "Enter factor: ";
cin >> factor;
cout << "" <<endl;

bondCost = ((quantity*price*factor)/100);


cout.setf(ios::showpoint);
cout.precision(2);

cout << "The pricipal on this bond is: " << bondCost;

return 0;

}

sorry, i forgot something... it looks like this

cout.setf(ios::fixed, ios::floatfield);
cout.setf(ios::showpoint);
cout.precision(2);

go ahead and try it

Drizzle,

That worked perfectly. What do the fixed and floatfield arguments do? I have not come across those yet?

Thanks.

i duno... probably set something in the cout function. i learned it from my teacher while doing a program..... any other tricks you need, just ask