title: Why this code removes first 3 char?
body: <p>I'm learning C and I find this program but I couldn't understand why it removes first three char. What's the math behind this?</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  #include &lt;conio.h&gt;
  
  void main(void){
      int *ptr;
      char *str="hello world";
      char *s_ptr;
      ptr = (int *)str;
      ptr++;
      s_ptr = (char *) ptr;
      printf("%s", --s_ptr);
      _getch();
  }
  </code></pre>