uninitialized?, tuitionCost, local Variable, [closed] - c++

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int main()
{
double tuitionCalc(int sumCreditHoursTaken);
int numCourses;
double total = 0.0;
double tuitionCost= 0.0;
cout << "\t\t This Program calculates a student's total number of\n";
cout << "\t\tcredit hours and tution for a given semester.\n";
cout << "\nPlease enter the number of Courses you will be taking this semester: ";
cin >> numCourses;
for ( int count = 1; count <= numCourses; count++)
{
double sumCreditHoursTaken;
cout << " please enter the number of credit hours for course" << count << ": ";
cin >> sumCreditHoursTaken;
total += sumCreditHoursTaken;
}
cout << fixed << showpoint << setprecision(2);
cout << "Your Total number of credit hours is: " << total << endl;
cout << "Your total tuition will be: $" << tuitionCalc(tuitionCost) << "\n\n";
return 0;
}
and the function im calling is
double tuitionCalc(int sumCreditHoursTaken)
{
double tuitionCost = 0.0;
double costCreditHour = 147.00;
double maxHoursFullTuition = 12;
double maintFeeAddOn = 29.33;`
if (sumCreditHoursTaken <= maxHoursFullTuition)
cout<< " " << (sumCreditHoursTaken * costCreditHour);
else if (sumCreditHoursTaken > maxHoursFullTuition)
cout << " " << (maxHoursFullTuition * costCreditHour) + ((sumCreditHoursTaken - maxHoursFullTuition) * maintFeeAddOn);
return tuitionCost;
}
input for number of courses is 5
and credit hours is 3,3,3.5,4,2.5
i get the total credit hours but icant seem to display the tuition cost?
thank you s

Answer 1

You are never actually assigning a value to tuitionCost in tuitionCalc() method, so it will always be 0.0.
To elaborate: You are returning tuitionCost from tuitionCalc(). You first initialize tuitionCost = 0.0, but never proceed to assign any calculated value to it. Thus, when you return tuitionCost, it will return the value you initialized it to: 0.0.

Answer 2

I haven't examined your code in detail, but if you inputs contain floating point numbers then change the type for sumCreditHoursTaken from int to double.
Also, change the parameter for the invocation of tuitionCalc from tuitionCost to total.

Answer 3

It seems that OP has fallen afoul of misunderstanding scope and how variables are passed to functions.
In main, OP defines tuitionCost. tuitionCalc defines another tuitionCost. These are different tuitionCosts. They represent different locations in memory and can store different values.
Next, because the tuitionCalc function is defined
double tuitionCalc(int sumCreditHoursTaken)
tuitionCalc(tuitionCost) will take tuitionCost convert it to an integer, and pass a copy into tuitionCalc where it will be used with the name sumCreditHoursTaken. One could say OP has three tuitionCalcs at this point. Not what they want.
Breaking down the tuitionCalc prototype, we see that it takes sumCreditHoursTaken, an integer and based on the name the number of credit hours taken, not a total cost. tuitionCalc also returns a double and inferring the purpose of the function from it;'s name, one would expect that it calculates and returns the tuition.
Like Anatoly states in his answer, the input to tuitionCalc should almost certainly be total, the total number of credit hours computed, and the output should be tuitionCost.
Since this has the smell of a homework assignment, it's not in the OP's best interests to fully answer the question. Instead here are a few recommendations:
Eliminate tuitionCost from main. It only serves to increase confusion. You can reuse variable names, but only do it where there is a clear benefit. If you have a cost and a function that takes and uses cost, then using cost for both makes sense. Just remember that cost inside the function is a different entity unless you pass by reference. In
void function(int & cost)
called with
function(cost);
both costs are the same. But in
void function(int cost)
called with
function(cost);
both function's cost is a copy of the caller's cost and any changes made by function will only effect the copy.
Declare variables close to where you use them. This way people reading your code don't have to scroll up and down and otherwise go hunting. It also helps you because it makes mistakes like, "Why am a calling a function that takes an int with a double?" more obvious.
Do not cout in tuitionCalc. Compute and return tuitionCost. Allow main to output tuitionCost. A function with a name like calc should only calculate. Names should describe function as closely as possible.

Answer 4

First of all you should create the function prototype before declaring it.
And there were some confusions in the code you have used I tried my best to omit error hope this is helpful!
#include <iostream>
#include <iomanip>
using namespace std;
double tuitionCal(double sumCreditHoursTaken);
int main() {
double tuitionCalc(int sumCreditHoursTaken);
int numCourses;
double total = 0.0;
//double tuitionCost= 0.0;
cout << "\t\t This Program calculates a student's total number of\n";
cout << "\t\tcredit hours and tution for a given semester.\n";
cout << "\nPlease enter the number of Courses you will be taking this semester: ";
cin >> numCourses;
double sumCreditHoursTaken; // you should create this variable outside the for loop
for ( int count = 1; count <= numCourses; count++)
{
cout << " please enter the number of credit hours for course" << count << ": ";
cin >> sumCreditHoursTaken;
total += sumCreditHoursTaken;
}
double tuitionCost=tuitionCal(total);
cout << fixed << showpoint << setprecision(2);
cout << "Your Total number of credit hours is: " << total << endl;
cout << "Your total tuition will be: $" <<tuitionCost<< "\n\n";// I assume this is what you want
return 0;
}
double tuitionCal(double sumCreditHoursTaken)//the parameter type is double now
{
double tuitionCost = 0.0;
double costCreditHour = 147.00;
double maxHoursFullTuition = 12;
double maintFeeAddOn = 29.33;
if (sumCreditHoursTaken <= maxHoursFullTuition)
tuitionCost=(sumCreditHoursTaken * costCreditHour);
else if (sumCreditHoursTaken > maxHoursFullTuition)
tuitionCost=(maxHoursFullTuition * costCreditHour) + ((sumCreditHoursTaken - maxHoursFullTuition) * maintFeeAddOn);
return tuitionCost;
//I don't see a point of returning the value and couting both you can
//do only one of the oprations
}