title: error C2371: 'functionname' redefinition: different basic types
body: <p>i have a Problem. I use Visual Studio 2013 and get the following Error:</p>
  
  <pre><code>Error C2371: 'getgrundflaeche' redefinition: different basic types.
  </code></pre>
  
  <p>I don't know why i get this Error. I get the same Error with VS12, when i try to call the function <code>getgrundflaeche()</code>.</p>
  
  <p>Here is the Code:</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  #define PI 3.14159265359
  
  int main(void){
      double h = 0, d = 0, r = 0, G = 0, V = 0, M = 0, O = 0;
  
      printf("Geometrie Zylinder:\nBitte geben sie den Durchmesser d ein (cm): ");
      scanf_s("%lf", &amp;d);
      printf("Bitte geben sie die Höhe h ein (cm): ");
      scanf_s("%lf", &amp;h);
      r = d / 2;
  
      G = getgrundflaeche(r);
      /*V = get_volumen(r, h);
      M = get_mantelflaeche(d, h);
      O = get_oberflaeche(M, G); */
  
      system("CLS");
  
      printf("Eingaben:\nDurchmesser d: %lf cm\nHöhe h: %lf cm", d, h);
      system("PAUSE");
  
      return 0;
  }
  
  double getgrundflaeche(double r){
      return (r*r);
  }
  /*
  double get_volumen(double r, double h){
  return r*r*h*PI;
  }
  
  double get_mantelflaeche(double d, double h){
  return d*h*PI;
  }
  
  double get_oberflaeche(double M, double G){
  return M+2*G;
  }*/
  </code></pre>