Displays 0.00 instead of Correct Tax.

[Tstan]

For some reason this code only displays 0.00 when it should display monthly tax! PLEASE HELP

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



double computeTax(double monthlyincome)
{
   double yearlyincome;
   double yearlytax;
   double monthlytax;
   {
   yearlyincome = (monthlyincome * 12);

      if (yearlyincome > 0 && yearlyincome <= 15100)
         yearlytax = (yearlyincome * .10);
      else if (yearlyincome > 15100 && yearlyincome <= 61300)
         yearlytax = 1510 + .15 * (yearlyincome - 15100);
      else if (yearlyincome > 61300 && yearlyincome <= 123700)
         yearlytax = 8440 + .25 * (yearlyincome - 61300);
      else if (yearlyincome > 123700 && yearlyincome <= 188450)
         yearlytax = 24040 + .28 * (yearlyincome - 123700);
      else if (yearlyincome > 188450 && yearlyincome <= 336550)
         yearlytax = 42170 + .33 * (yearlyincome - 188450);
      else if (yearlyincome > 336550)
         yearlytax = 91043 + .35 * (yearlyincome - 336550);

   monthlytax = (yearlytax / 12);
   }
   return (monthlytax);
}

int main()
{
   cout.setf(ios::fixed);
   cout.setf(ios::showpoint);
   cout.precision(2);
   double yearlytax;
   double monthlyincome;
   double monthlytax;
   cout << "Income: ";
   cin >> monthlyincome;
   cout << "\n"
        << computeTax(monthlytax);
   return 0;
}

[Edward01]

try this: double computeTax(double& monthlyincome) <---send by reference

[Tstan]

i put in computeTax(double& monthlyincome) and there was no change in the output :(

[Branflakes91093]

I think line 44 should be << computeTax(monthlyincome);

[Edward01]

foudn it: cout << "\n"
<< computeTax(monthlytax); here you send monthlytax which is zero.. and that's why you get zero.. you need to send monthlyincome..

[Tstan]

That was it!! Thank you! Why is it monthlyincome and not monthly tax I thought that was what was being returned?

[Edward01]

when you send something to other function, it's not necessarily what you want to be returned. it's just something you want to work with and the function can return something else depending on your needs. in that case you sent monthlytax but as you can see the value of it before you send it is NULL. because it's NULL than by this comand: yearlyincome = (monthlyincome * 12); your yearlyincome also became NULL, therefore you got zero all the time