Functions Calling Functions

[PDB1982]

How can I call a value that was created in 1 function into another function so that it can be used as a variable? (i.e how do I implement the values that I found in my distance function, and use them in my radius function...)

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

double distance(double center1, double center2, double point1, double point2);
double radius(double distance3);

int main()
{
	double center1, center2, point1, point2, distance3;

	cout << "Please Enter X-Value of Center: ";
	cin >> center1;
	cout << "Please Enter Y-Value of Center: ";
	cin >> center2;
	cout << endl;

	cout << "Please Enter X-Value of Point: ";
	cin >> point1;
	cout << "Please Enter Y-Value of Point: ";
	cin >> point2;
	cout << endl;

	cout << "Distance between Points: " << distance(center1,center2,point1,point2);
	cout << endl;
	cout << "Radius: " << radius(distance3);
	cout << endl;

} //End of Main

double distance(double center1, double center2, double point1, double point2)
{
	double distance1, distance2, distance3;

	distance1 = pow((point1 - center1), 2); 
	distance2 = pow((point2 - center2), 2);	
	distance3 = pow((distance1 + distance2), 0.5);

	return distance3;
}

double radius(double distance3)
{
	double rad;

	rad = distance3 / 2;

	return rad;
}

[restrictment]

You have to send the variable back to the main function, and implement it into the second function. You can do this using the ampersand character, '&'.

IE

function(double & value)
{
     double value = 3;
}
function2(double & value)
{
     cout << value;
}
main()
{
     function(value);
     function2(value);
}

[PDB1982]

You have to send the variable back to the main function, and implement it into the second function. You can do this using the ampersand character, '&'.

IE

function(double & value)
{
     double value = 3;
}
function2(double & value)
{
     cout << value;
}
main()
{
     function(value);
     function2(value);
}

This is going to sound bad, but can you use the terms from my code please.....I'm not sure what you mean otherwise....I'm not clear on function(double & value).....how would I code it cor the radius portion?

double radius(double and distance3)

[jonsca]

This is going to sound bad, but can you use the terms from my code please.....I'm not sure what you mean otherwise....I'm not clear on function(double & value).....how would I code it cor the radius portion?

In this case, since your functions are returning values (radius returns a double and distance returns a double) you can just grab those values into a local variable in main()

e.g.

int main()
{
            your other variables
            double dist, rad;

            further down....
 
            dist = distance(center1,center2, etc);
            rad = radius(center3);
             
}

Now instead of just outputting those to a cout (which was implicitly using the return value anyway) you can do whatever you want with them. e.g., double halfdist = dist/2; .

What restrictment says is technically correct, but since you have the return values (and only need 1 per function) you can go ahead and get them in the traditional way. If you wanted to, you could create a reference variable dist and send it in with your arguments, but just stick with what you have for now.