title: function does not take 1 arguments c++
body: <p>I'm having issue with my code, in that I can't figure out why I'm receiving an error. Here is the code:</p>
  
  <pre><code>using namespace std;
  
  void presentValue();
  bool stringChar();
  bool stringVal();
  double futureValConv();
  
  int main()
  {
    cout &lt;&lt; "Welcome to the Present Value Interest Calculator!\n\"First, let me collect some data." &lt;&lt; endl &lt;&lt; endl;
    presentValue();
    return 0;
  }
  
  void presentValue()
  {
    //declare variables
    //Response value intialized as x for debugging
    char response = 'x';
  
    while (response != 'n' || response != 'N')
    {
      //declare variables
      double intRate = 0;
      string futureValString;
      double futureVal;
      double years = 0;
  
      //Simple present value equation
      double presentVal = futureVal / pow((intRate + 1), years);
  
      cout &lt;&lt; "What's your Interest Rate?  ";
      cin &gt;&gt; intRate;
      cout &lt;&lt; "OK, and what's your desired Future Value? [H}elp  ";
      cin &gt;&gt; futureVal;
      //Run descending help program that won't allow escape without a double value
      **futureVal = futureValConv(futureValString);**
      cout &lt;&lt; endl &lt;&lt; endl &lt;&lt; "And finally, how many years would you like to save your money for?  ";
      cin &gt;&gt; years;
      cout &lt;&lt; endl &lt;&lt; "You've made it this far!!!";
      cout &lt;&lt; endl &lt;&lt; endl &lt;&lt; presentVal;
  
    }
  }
  inline double futureValConv(string somestring)
  {
    //delcare variables
    double newString = 0;
  
    **if (stringChar(somestring))**
    {
      cout &lt;&lt; endl &lt;&lt; "Future Value is the amount you would like to have in your account in the future.\n\n";
      cout &lt;&lt; "How much might that be?  ";
      cin &gt;&gt; somestring;
      futureValConv(somestring);
  
    }
    **else if(stringVal(somestring))**
    {
      //Convert the Future Value String to a double for future use
      newString = atoi(somestring.c_str());
    }  
    else
    {
      cout &lt;&lt; "Please enter a proper value.  ";
      futureValConv(somestring);
    }
  
    return newString;
  }
  
  bool stringChar(string response)
  {
    //declare variables
    char answer = response[0];
    bool status = false;
  
    if (answer == 'H' || answer == 'h')
    {
      status = true;
      return status;
    }
  }
  
  bool stringVal(string response)
  {
    //declare varialbes
    int answer = atoi(response.c_str());
    bool status = false;
    int powZero = (answer, 0);
  
    if (powZero == 1)
    {
      status = true;
      return status;
    }
  
  }
  </code></pre>
  
  <p>I posted most of my code because I can't grasp what is going on here.  It is telling me that stringChar and stringVal do not take 1 arguments, as well as futureValConv. I am attempting to run a function checking the value of a string, and determining what the value is before making a decision. In two of the three instances, the function calls itself to run again until the user has entered an acceptable double (Which I check by running to the power of 0 for a an answer of 1.) I have bolded the three lines generating an error. Interestingly, even by commenting out the function futureValConv and never calling into the other functions, I still get two of the three errors.</p>