Please help me, about decimal in C++..

[geezle86]

So, i wrote this code:

 //On a certain day the British pound was equivalent to $1.487 U.S., the French franc was
//$0.172, the German deutschemark was $0.584, and the Japanese yen was $0.00955.
//Write a program that allows the user to enter an amount in dollars, and then displays this
//value converted to these four other monetary units.

#include <iostream>
#include <iomanip>

using namespace std;

int main()
{
    float pound = 1.478;
    float franc = 0.172;
    float deutschemark = 0.584;
    float yen = 0.00955;
    int dollar;
    int menu;

    pound = dollar/pound;
    franc = dollar/franc;
    deutschemark = dollar/deutschemark;
    yen = dollar/yen;

    cout << "Money Changer:" << endl << endl;
    cout << "1. Input ammount ($)" << endl << "2. Exit" << endl << "How can I help you: ";
    cin >> menu; cout << endl;

    if(menu==1)
    {
        cout << "Insert the ammount: ";
        cin >> dollar; cout << endl;

        cout << "The money you converted: " << endl;
        cout << "Pound= " << setprecision(2) << pound << endl << "Franc= " << setprecision(2) << franc
        << endl <<"Deutschemark= " << setprecision(2) << deutschemark << endl << "Yen= " << setprecision(2) << yen << endl;
    } else

    if(menu==2)
    {
        cout << "Thanks for using our service." << endl;
    }

    else
    {
        cout << "Please select the menu number provided." << endl;
    }

    return 0;
}

and the output:

Money Changer:

1. Input ammount ($)
2. Exit
How can I help you: 1

Insert the ammount: 10000

The money you converted:
Pound= 1.6e+006
Franc= 1.4e+007
Deutschemark= 4e+006
Yen= 2.5e+008

Process returned 0 (0x0)   execution time : 3.539 s
Press any key to continue.

My question is:

1. How to display the decimal without the 'e'?
2. And also, how to display only the last 2 digits after the comma?

Thanks,
God bless you

[mutexe]

that shouldn't be your main concern.

You have not initialised dollar, which is why your maths is cack.

[geezle86]

Any other else want to help me?

[mutexe]

READ MY POST.
Or do you seriously think 10 thousand dollars is the equivalent of 1.6 million english pounds?

[Chervil]

I would make these values into constants:

    const float pound = 1.478;
    const float franc = 0.172;
    const float deutschemark = 0.584;
    const float yen = 0.00955;

Don't attempt to assign any other value, for example don't do this: pound = dollar/pound;
Instead, define new variables for any subsequent calculations.
For a single calculation it would not matter very much, but if the user needed to enter a series of different dollar amounts, you'd want the original conversion rates to remain unaltered.

As well as that, you can't carry out the actual conversion until after line 32:
cin >> dollar;
That is, until the user has entered the value for dollar, it isn't possible to convert that amount into any other currency.

as for the original question, try
cout << fixed << setprecision(2);

[mutexe]

he's doing the calculations before he's asked the user for input :s

[geezle86]

Oh my god mutexe was right.. Im sorry, im really sorry, hahahaha thx mutexe

[geezle86]

Wait a minute, question number two still a problem. So i change the code like this:

cout << "The money you converted: " << endl;
cout << "Pound= " << p << setprecision(2); 
cout << endl << "Franc= " << f << setprecision(2);
cout << endl <<"Deutschemark= " << d << setprecision(2);
cout << endl << "Yen= " << y << setprecision(2);
cout << endl;

and still not showing only the last 2 digits :S

[Chervil]

You missed part of my previous comment:
cout << fixed;
Also, this must go before the actual values you wish to output, not afterwards.

[geezle86]

Thanks Chervil, God bless you :)

[andywestken]

BTW...

All standard i/o manipulators which set or reset something, with the exception of setw, are "sticky" (i.e. do not reset after use); so the above could also be written as (with fixed added):

cout << "The money you converted: " << endl;
cout << setprecision(2) << fixed;
cout << "Pound= " << p; 
cout << endl << "Franc= " << f;
cout << endl <<"Deutschemark= " << d;
cout << endl << "Yen= " << y;
cout << endl;

or even as a single cout statement, as you had originally.

cout << "The money you converted: " << endl
     << setprecision(2) << fixed
     << "Pound= " << p << endl
     << "Franc= " << f << endl
     << "Deutschemark= " << endl
     << "Yen= "   << y << endl
     << endl;
    // endls look better at the ends of lines to me... 

Andy

PS
- the i/o manipulators that don't set/reset anything those which do something: endl, ends, flush and the new C++ manips: get_money, put_money, get_time, put_time.
- the sticky manipulators are all setting a flag
- setw behave the way is does as that's what ios_base method it calls (width) does itself.

    cout << "set width to 8\n\"";
    cout.width(8);
    cout << f;
    size_t w = cout.width();
    cout << "\"\n\"width = " << w << "\"" << endl;

set width to 8
"     2.3"
"width = 0"