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#1 chelitoz_4  Icon User is offline

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Making a calculator using functions

Post icon  Posted 17 May 2009 - 08:37 PM

Hi. I was trying to make a calculator using functions. The functions Include; add, multiplications, subtract, division, raise to power, square root, roots of polynomial of second degree, square root, average, and obviously a quit code to finish the application. The calculator, after choosing an options, it must ask the user if they want to make a new computation, if user enters NO, the calculator should end. I CANT USE CMATH LIBRARY... Please help me!...I started the code, but I dont know how to ask the user to use a option (add, multiply etc). I started it like this...

 #include <iostream>
using namespace std;
double func, Sum(), Mult(), Subt(), Div(), Raise(), Roots(), Square(), Avg(), Quit;
int main()
{
	double result;
	cout<<"  ***Welcome to my calculator*** "<<endl;
	cout<<"Select one of the following options: "<<endl;
	cout<<"\t 1- Add"<<endl;
	cout<<"\t 2- Multiplication"<<endl;
	cout<<"\t 3- Subtract"<<endl;
	cout<<"\t 4- Division"<<endl;
	cout<<"\t 5- Raise to power"<<endl;
	cout<<"\t 6- Roots of Polynomial of Second Degree"<<endl;
	cout<<"\t 7- Square Root"<<endl;
	cout<<"\t 8- Average"<<endl;
	cout<<"\t 9- Quit"<<endl;
	cout<<"Enter a option: ";
	cin>>func;
	result=Mult();
	cout<<"Result is "<<result<<endl;
	system("pause");
	return 0;
}
double Mult()
{
	   
	   int n, count;
	   double total=1,num;
	   cout<<"How many numbers do you want to calculate: ";
	   cin>>n;
	   for (count=0;count<n;count++)
	   {
		   cout<<"Enter a value: ";
		   cin>>num;
		   total= total*num;
		   }
	   return total;
		   }



Im making the functions on different source files. I make the multiply and add. And I have no idea how to make this. I hope you can help me..

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#2 xCraftyx  Icon User is offline

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Re: Making a calculator using functions

Posted 17 May 2009 - 08:41 PM

What i usually do for menus like this is use a switch statement to manage the choices. As for the multiple computations part, use a while loop that will continue to execute unless the user chooses not to perform another computation (either through a boolean test or a break statement)
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#3 AGRAC393  Icon User is offline

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Re: Making a calculator using functions

Posted 18 May 2009 - 05:35 AM

View Postchelitoz_4, on 17 May, 2009 - 07:37 PM, said:

Hi. I was trying to make a calculator using functions. The functions Include; add, multiplications, subtract, division, raise to power, square root, roots of polynomial of second degree, square root, average, and obviously a quit code to finish the application. The calculator, after choosing an options, it must ask the user if they want to make a new computation, if user enters NO, the calculator should end. I CANT USE CMATH LIBRARY... Please help me!...I started the code, but I dont know how to ask the user to use a option (add, multiply etc). I started it like this...

 #include <iostream>
using namespace std;
double func, Sum(), Mult(), Subt(), Div(), Raise(), Roots(), Square(), Avg(), Quit;
int main()
{
	double result;
	cout<<"  ***Welcome to my calculator*** "<<endl;
	cout<<"Select one of the following options: "<<endl;
	cout<<"\t 1- Add"<<endl;
	cout<<"\t 2- Multiplication"<<endl;
	cout<<"\t 3- Subtract"<<endl;
	cout<<"\t 4- Division"<<endl;
	cout<<"\t 5- Raise to power"<<endl;
	cout<<"\t 6- Roots of Polynomial of Second Degree"<<endl;
	cout<<"\t 7- Square Root"<<endl;
	cout<<"\t 8- Average"<<endl;
	cout<<"\t 9- Quit"<<endl;
	cout<<"Enter a option: ";
	cin>>func;
	result=Mult();
	cout<<"Result is "<<result<<endl;
	system("pause");
	return 0;
}
double Mult()
{
	   
	   int n, count;
	   double total=1,num;
	   cout<<"How many numbers do you want to calculate: ";
	   cin>>n;
	   for (count=0;count<n;count++)
	   {
		   cout<<"Enter a value: ";
		   cin>>num;
		   total= total*num;
		   }
	   return total;
		   }



Im making the functions on different source files. I make the multiply and add. And I have no idea how to make this. I hope you can help me..



Hello,

I have a simple form of a calculator but I don't know if it will help you in your case! I didn't use cmath, so that may help. If all fails, then mabey it will give you an idea.
#include <cstdlib>
#include <iostream>
#include <windows.h>
 
using namespace std;
 
int main()
{
	double num;
	double num2;
	char choice;
	for (;;){
	 do {
	cout<<"Please choose an option by entering the number, press q to quit\n";
	cout<<"\n";
	cout<<"1 - Addition\n";
	cout<<"2 - Subtraction\n";
	cout<<"3 - Division\n";
	cout<<"4 - Multiplication\n";
	cout<<"\n";
	cout<<"\n";
	cin>>choice;
	} while ( choice < '1' || choice > '7' && choice != 'q');
	if (choice == 'q') break;
	switch (choice) {
		   case '1':
				cout<<"Please enter a number\n";
				cout<<"\n";
				cin>>num;
				cout<<"Another number to be added\n";
			   cout<<"\n";
				cin>>num2;
				cout<<num + num2;
				cout<<"\n";
				break;
		   case '2':
				cout<<"Please enter a number\n";
				cout<<"\n";
				cout<<"\n";
				cin>>num;
				cout<<"Another number to be subtracted\n";
				cout<<"\n";
				cout<<"\n";
				cin>>num2;
				cout<<num - num2;
				cout<<"\n";
				break;
		   case '3':
				cout<<"Please enter a number\n";
				cout<<"\n";
				cout<<"\n";
				cin>>num;
				cout<<"Another one to be divided\n";
				cout<<"\n";
				cout<<"\n";
				cin>>num2;
				cout<<num / num2;
				cout<<"\n";
				break;
		   case '4':
				cout<<"Please enter a number\n";
				cout<<"\n";
				cout<<"\n";
				cin>>num;
				cout<<"Another one to be multiplied\n";
				cout<<"\n";
				cout<<"\n";
				cin>>num2;
				cout<<"\n";
				cout<<"\n";
				cout<<"\n";
				cout<<"The answer is ";
				cout<<num * num2;
				cout<<"\n";
				cout<<"\n";
				break;
				}
 
}
return 0;


}


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