title: printf in Eclipse
body: <p>I have to work with eclipse in C. I wrote a simple program, but I have a problem with a <code>printf</code> command which doesn't work properly. Any idea? 
  Here is the code :</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  void change(double *x, double *y)
  {
   double help = *x;
    *x = *y;
   *y = help;
   return;
  }
  
  int main()
  {
  double x=0, y=0;
  
  printf("please give a value to a  \n ");
  scanf("%f",&amp;x);
  printf("please give a value to b  \n");
  scanf("%f",&amp;y);
  
  printf("x=%.2f\t y=%.2f\n",x,y);
  printf("will give \n");
  change(&amp;x,&amp;y);
  printf("x=%.2f\t y=%.2f\n",x,y);
  return 0;
  }
  </code></pre>
  
  <p>So the problem is that I dont't get this first <code>printf</code>. </p>