Thanks for replying again. I applied everything you told me to do except the last 2 parts when you explained about the "final grade" and "total points" part. I didn't quite understand that part. I'm new to C++, so I don't quite understand a lot of the terminology yet. My program runs now (which is a good thing).
It's my bad for assuming you'd understand the terminology used. I'll try to make a quick example of what I mean on the last 2 points.
Here is simply a copy of the code/function with my comments so you don't have to keep scrolling up & down the page too much.
void printresults(double testpoints,double labpoints,double finalexampoints,double projectpoints,double& finalgrade)
{
double totalpoints;
double testscores;
double labscores;
double projectscores;
double finalexamscores;
double finalgrade; /*finalgrade is redfined here, but overall if you're passing by value & reference you shouldn't need these if you're expecting to use values passed to the function & should only define local variables if you expect them to only be used locally in a function.*/
totalpoints = (testscores + labscores + projectscores + finalexamscores); /*If you meant to use the variables passed into this function then use the variables in the argument list that is use 'testpoints', 'labpoints' that are in the function argument list if that is what you were meaning to do*/
cout<<"Test points: "<<testscores<<endl;
cout<<"Lab points: "<<labscores<<endl;
cout<<
"Project points: "<<projectscores<<endl;
cout<<"Final Exam points: "<<finalexamscores<<endl;
cout<<"Total points: "<<totalpoints<<endl;
cout<<"Final Grade: "<<finalgrade<<endl;
}
Starting with re-defined, the variable finalgrade was passed into printresults() near the end you see the last argument double& finalgrade, the other variables you made in there aren't needed however as they would all be created with a default value (usually 0) so what you'd have as output in that function is
Test points: 0
Lab points: 0
etc
Because you're using newly created local variables which are unitialized, that is they have been assigned no values. When you have a function like
void printresults(double testpoints,double labpoints,double finalexampoints,double projectpoints,double& finalgrade)
what is happening is in main() where printresults is called, it passes testpoints, labpoints & all the other values, then in printresults, it automatically creates them as you create them, example.
#include <iostream>
using std::cout;
using std::cin;
using std::endl;
double printresults(double, double&, int, int&);
int main()
{
double d_value1 = 58.5;
double d_value2 = 33.7;
int i_value1 = 4;
int i_value2 = 7;
double ret_value;
ret_value = printresults(d_value1, d_value2, i_value1, i_value2);
cout << "d_value1 is: " << d_value1 << endl;
cout << "d_value2 is: " << d_value2 << endl;
cout << "i_value1 is: " << i_value1 << endl;
cout << "i_value2 is: " << i_value2 << endl;
cout << "ret_value is: " << ret_value << endl;
cin.get();
return 0;
}
double printresults(double d_value1, double &d_value2, int i_value1, int &i_value2)
{
cout << "printresults function-----------------\n";
cout << "d_value1 is: " << d_value1 << endl;
cout << "d_value2 is: " << d_value2 << endl;
cout << "i_value1 is: " << i_value1 << endl;
cout << "i_value2 is: " << i_value2 << endl;
cout << "endof printresults output-------------\n";
d_value1 = d_value1 * 10;
d_value2 = d_value2 * 5;
i_value1 = i_value1 * i_value1;
i_value2 = i_value2 * i_value1;
return d_value1 * d_value2;
}
Ok so in main() on line 17 as you can see main called the function "printresults" & sends 4 values, 2 by value, 2 by reference, the ones passed by reference are the ones with the ampersand in front of them (&) so basically d_value2 & i_value2 are the values sent by reference, now on line 29 you can see the function & it's argument list, but as you can see in the function itself I have not made anymore doubles or ints, I've simply used the names from that argument list to main multiply those variables in different ways.
So generally what I'm saying is if in the printresults() function I added say added a line to line 37 & added "double d_value1" that would be redefining a variable, since it is already made by the function when it were invoked.
For explaination sake aswell, just incase. If you noticed 2 of the numbers when displayed in main() don't change, while the others 2, if observant, you'll notice that the numbers that change are the ones passed by reference. That is, (double &d_value2, int &i_value2) have changed while (double d_value1, int i_value1) have not. Passing by value only passes by value, the function creates a copy in which you can change the value but the original in main() is not changed, while if you pass by reference you'll be passing the address of the variable & hence changing the actual value in main() which is why the 2 passed by reference show change in main() while the others passed by value are not.
So
totalpoints = (testscores + labscores + projectscores + finalexamscores);
should use the variable names from
double printresults(double testpoints,double labpoints,double finalexampoints,double projectpoints,double& finalgrade)
so perhaps it should look more like
totalpoints = (testpoints + labpoints + projectpoints + finalexampoints);
Hope what I meant is a little more clearer to you now.
Lerner answers other question, so not going to repeat!
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