title: square of a float number in C
body: <p>I have written a code in C which works fine for int but when I try to do this with float it is showing error what can i do to make it correct.</p>
  
  <pre><code>#include&lt;stdio.h&gt;
  
  int main()
  {
      float a,y;
      float square();
      scanf("%f", &amp;a);
      y = square( a );
      printf("%f %f ",a ,y);
  }
  
  float square(float b)
  {
      float z;
      z = b*b;
      printf("%f %f",z ,b);
      return(z);
  }
  </code></pre>
  
  <p>error:</p>
  
  <pre><code>return.c:12: error: conflicting types for 'square'
  return.c:13: note: an argument type that has a default promotion can't match an empty parameter name list declaration
  return.c:6: note: previous declaration of 'square' was here
  </code></pre>