loop and switch use in c++

martin330 · #1 (**permalink**) April 25th, 2010, 04:37 AM

Hello,

I am trying to develop the curreny exchange program and
unbale to use loop and switch statment in following code.

Please help us how can use the loop and switch statement in
following code to convert one currency to another.

Regards

#include <iostream.h>
#include <conio.h>

main()

{
int e,r,d;
int a,eu;
char convert,convertinto;

cout<<"Wellcome to Exchange of Currency Rates Program C++ " <<"\n" <<"\n";
cout<<"Foreign Cuurency Exchange Rates are following" <<"\n";
cout<<"-------------------------------------------- "<<"\n";
cout<<"1 Euro = 112 Rupees." <<"\n";
cout<<"1 Dollar = 84 Rupees." <<"\n";
cout<<"1 Euro = 1.33 Dollars." <<"\n";
cout<<"1 Dollar = 0.75 Euro " <<"\n";
cout<<"-------------------------------------------- "<<"\n";

cout<<"Please select currencies that you want to exchange." <<"\n";
cout<<"Description :" <<"\n";
cout<<"---------------------- "<<"\n";
cout<<"Enter 'R' for Pakistani Rupees." <<"\n";
cout<<"Enter 'E' for Euro." <<"\n";
cout<<"Enter 'D' for Dollar." <<"\n" <<"\n";

cout<<"Please select the correny that you want to convert.";
cin>>convert;

cout<<"Please select the correny that you want to convert into .";
cin>>convertinto;

cout<<"Please enter the amount in Euro :";
cin >>eu;

a = eu * 112;
cout<<eu<<" Euro = "<<a<<" "<<"Rupees"<<"\n"<<"\n";

cout<<"Press any key to Exit....";

getch();

}

PeterPeiGuo · #2 (**permalink**) April 25th, 2010, 12:51 PM

Store exchange rate in an array, that makes the code neat: (The following is good enough as a simple example. In real life you obviously need to validate the input etc.)

Code:

#include <iostream.h>
#include <conio.h>

int main()
{
	enum Currency {Rupee, Euro, Dollar};
	float rate[3][3];
	rate[Rupee][Rupee] = 1.;
	rate[Rupee][Euro] = 2.;
	rate[Rupee][Dollar] = 4.;
	rate[Euro][Rupee] = 0.5;
	rate[Euro][Euro] = 1.;
	rate[Euro][Dollar] = 2.;
	rate[Dollar][Rupee] = 0.25;
	rate[Dollar][Euro] = 0.5;
	rate[Dollar][Dollar] = 1.;

	int from, to;
	float amount;
	char quit;

	while (1) {
		cout<<"0 - Rupee\n";
		cout<<"1 - Euro\n";
		cout<<"2 - Dollar\n"; 

		cout<<"Please select the correny that you want to convert:";
		cin>>from;

		cout<<"Please enter the amount:";
		cin >>amount;

		cout<<"Please select the correny that you want to convert into:";
		cin>>to;

		cout << "Current exchange rate is: " << rate[from][to] << "\n";
		cout << "Converted amount: " << amount * rate[from][to] << "\n";
		
		cout << "Quit? (y/n) ";
		cin >> quit;
		if (quit == 'y') return 0;
	} 
}

martin330 · #3 (**permalink**) April 25th, 2010, 11:18 PM

Thanks your very much for your help.

Regards