Trouble Coding Compound Interest

Question

I'm trying to calculate compound interest using the formula
A = P(1 + r/12)^(12t)
My error code is saying the compoundInterest must return a value but Visual Studio isn't telling me which line the error is.

#include <iostream>
#include <math.h>

using namespace std;
double compoundInterest(double P, double r, int t);

int main (void)
{
double P, r;
int t;
cout << "This app is used to calculate the compound interest in an account. " << endl;

cout << "Enter the principal in the account: " << endl;
cin >> P;

cout << "Enter the annual rate for the account as a percent: " << endl;
cin >> r;

cout << "Enter the time in number of years: " << endl;
cin >> t;

cout << "Balance of account after interest: " << compoundInterest( P, r ,t) << endl;

return 0;

}

double compoundInterest(double P, double r, int t)
{
double A = P * pow(1 + r / 12, 12);

system("pause");

}

Answer 1

Try changing your function to this:

double compoundInterest(double P, double r, int t) {
double A = P * pow(1 + r / 12, 12*t);
return A;
}

The reason why it wasn't working is because your function must return a double but it wasn't returning anything.

Answer 2

Thank you. It fixed the problem.