How to turn if else statements from math....into functions???

lilballeer · #1 12-May-2008, 08:04

Hello,

I got the program to work as follows: but i need to convert everything to functions.
Here is the program working before I tried converting to functions:

CPP / C++ / C Code:

#include <iostream>
#include <cstdlib>
#include <ctime> 

using namespace std;

int main ()

{

	double x;
	double y;
	char choice;
	double youranswer; 
	double answer; 
	double z;

do
{
	x = (rand() + time(0)) % 10;


	cout << "The 'random number' is: " ; 
		cout << x << endl;
y = (rand() + time(0)) % 10;


	cout << "The 'random number' is: " ; 
		cout << y << endl;

cout << "Please select one of the following options" << endl;
cout << "A - for addition" << endl;
cout << "D - for division" << endl;
cout << "M - for multiplication" << endl;
cout << "S - for subtraction" << endl;
cout << "Q - to quit the program" << endl;

cin>>choice; 


if (choice == 'A')
{
cout << "Add" << x << "+" << y << endl;
answer = x + y;
cin >> youranswer;
if (youranswer == answer)
cout << "your answer is correct"<< endl;
	else 
		cout << "Incorrect Answer: the correct answer is: " << answer << endl; 

}
else
if (choice == 'S')
{
	if ( x >= y )
	{ 
		answer = x - y;
	cout << "Subtract: " << x << "-" << y << endl;
	}
	else 
	{
		answer = y - x;
	cout << "Subtract: " << y << "-" << x << endl;
	}
	
	cin >> youranswer;
	if (youranswer == answer)
		cout << "Your answer is correct!!!" << endl;
	else
		cout <<"Incorrect Answer: the correct answer is: " << answer << endl;
}
else
if (choice == 'M')
{
	cout << "Multiplicate: " << x << "*" << y << endl;
	answer = x * y;
	cin >> youranswer;
	if (youranswer == answer)
		cout << "Your answer is correct!!!" << endl;
	else
		cout <<"Incorrect Answer: the correct answer is: " << answer << endl;
}
else 
if (choice == 'D')
{
	z = x * y;
cout << "Divide: " << z << "/" << x << endl;
	answer = z / x;
	cin >> youranswer;
	if (youranswer == answer)
		cout << "Your answer is correct!!!" << endl;
	else
		cout <<"Incorrect Answer: the correct answer is: " << answer << endl;
}
}

while (choice != 'Q'); 
cout << "Goodbye" << endl;

return 0; 


}

and here is my attempt at just converting the add function:

CPP / C++ / C Code:


#include <iostream>
#include <cstdlib>
#include <ctime> 

using namespace std;
double add (double x, double y);

int main ()

{

	double x;
	double y;
	char choice;
	double youranswer; 
	double answer; 
	double z;

do
{
	x = ((rand() + time(0)) % 10) + 1; //add 1 so 0 does not come up 


	cout << "The 'random number' is: " ; 
		cout << x << endl;
y = ((rand() + time(0)) % 10) + 1;


	cout << "The 'random number' is: " ; 
		cout << y << endl;

cout << "Please select one of the following options" << endl;
cout << "A - for addition" << endl;
cout << "D - for division" << endl;
cout << "M - for multiplication" << endl;
cout << "S - for subtraction" << endl;
cout << "Q - to quit the program" << endl;

cin>>choice; 


if (choice == 'A')
{
cout << "Add" << x << "+" << y << add(double x, double y) << endl;
answer = x + y;
cin >> youranswer;


}
else
if (choice == 'S')
{
	if ( x >= y )
	{ 
		answer = x - y;
	cout << "Subtract: " << x << "-" << y << endl;
	}
	else 
	{
		answer = y - x;
	cout << "Subtract: " << y << "-" << x << endl;
	}
	
	cin >> youranswer;
	if (youranswer == answer)
		cout << "Your answer is correct!!!" << endl;
	else
		cout <<"Incorrect Answer: the correct answer is: " << answer << endl;
}
else
if (choice == 'M')
{
	cout << "Multiplicate: " << x << "*" << y << endl;
	answer = x * y;
	cin >> youranswer;
	if (youranswer == answer)
		cout << "Your answer is correct!!!" << endl;
	else
		cout <<"Incorrect Answer: the correct answer is: " << answer << endl;
}
else 
if (choice == 'D')
{
	z = x * y;
cout << "Divide: " << z << "/" << x << endl;
	answer = z / x;
	cin >> youranswer;
	if (youranswer == answer)
		cout << "Your answer is correct!!!" << endl;
	else
		cout <<"Incorrect Answer: the correct answer is: " << answer << endl;
}
}

while (choice != 'Q'); 
cout << "Goodbye" << endl;

return 0; 


}

double add (double x, double y) 
{

if (youranswer == answer)
return cout << "Your answer is correct"<< endl;
	else 
	return cout << "Incorrect Answer: the correct answer is: " << answer << endl; 
}

any help on just getting the add function to work...thank you

lilballeer · #2 12-May-2008, 16:58

Hello,

Hey I figured out how to get the functions to work... but for some reason i cant get the division to work when the program runs... it just exits out of the program... i believe it has something to do with unitialized z variable... can someone please help explain this....thank you

here is the code:

CPP / C++ / C Code:


#include <iostream>
#include <cstdlib>
#include <ctime> 

using namespace std;
void add (double x, double y);
void subtraction (double x, double y);
void multiplication (double x, double y);
void division (double x, double y, double z);
double answer;
double youranswer;


int main ()

{

	double x;
	double y;
	char choice;
	double youranswer; 
	double answer; 
	double z;

do
{
	x = ((rand() + time(0)) % 10) + 1; //add 1 so 0 does not come up 


	cout << "The 'random number' is: " ; 
		cout << x << endl;
y = ((rand() + time(0)) % 10) + 1;


	cout << "The 'random number' is: " ; 
		cout << y << endl;

cout << "Please select one of the following options" << endl;
cout << "A - for addition" << endl;
cout << "D - for division" << endl;
cout << "M - for multiplication" << endl;
cout << "S - for subtraction" << endl;
cout << "Q - to quit the program" << endl;

cin>>choice; 


if (choice == 'A')
{
add(x,y);



}
else
if (choice == 'S')
{
	
		subtraction (x,y); 
}
else
if (choice == 'M')
{
	multiplication (x,y);
	
}
else 
if (choice == 'D')
{
	division (x,y,z);
}
}

while (choice != 'Q'); 
cout << "Goodbye" << endl;

return 0; 


}

void add (double x, double y) 
{
answer = x + y;
cout << "Add" << x << "+" << y << endl;
cin>>youranswer; 
if (youranswer == answer)
 cout << "Your answer is correct"<< endl;
	else 
	 cout << "Incorrect Answer: the correct answer is: " << answer << endl; 
}

void subtraction ( double x, double y) 
{ 
	if ( x >= y )
	{ 
		answer = x - y;
	cout << "Subtract: " << x << "-" << y << endl;
	}
	else 
	{
		answer = y - x;
	cout << "Subtract: " << y << "-" << x << endl;
	}
	
	cin >> youranswer;
	if (youranswer == answer)
		cout << "Your answer is correct!!!" << endl;
	else
		cout <<"Incorrect Answer: the correct answer is: " << answer << endl;
}

void multiplication (double x, double y)
{
	cout << "Multiplicate: " << x << "*" << y << endl;
	answer = x * y;
	cin >> youranswer;
	if (youranswer == answer)
		cout << "Your answer is correct!!!" << endl;
	else
		cout <<"Incorrect Answer: the correct answer is: " << answer << endl;
}
void division (double x, double y, double z)
{
	z = x * y;
cout << "Divide: " << z << "/" << x << endl;
	answer = z / x;
	cin >> youranswer;
	if (youranswer == answer)
		cout << "Your answer is correct!!!" << endl;
	else
		cout <<"Incorrect Answer: the correct answer is: " << answer << endl;
}

lilballeer · #3 12-May-2008, 17:02

never mind.... can mods delete this thread??
I figured out that i needed to initialize z outside of the function...

fakepoo · #4 13-May-2008, 07:23

It may help you to validate your input in the functions. For instance, in the division function, check to make sure that the denominator is not zero.

lilballeer · #5 13-May-2008, 08:29

Quote:

Originally Posted by fakepoo

It may help you to validate your input in the functions. For instance, in the division function, check to make sure that the denominator is not zero.

Yes, I added 1 to the random function so that 0 does not come up as a variable... Thank you..

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How to turn if else statements from math....into functions???

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