title: why there is semicolon after loop while();
body: <p>I am reading a code of my friend an I see this: </p>
  
  <pre><code>#include &lt;stdio.h&gt;
  #include &lt;conio.h&gt;
  
  void main()
  {
      char string1[125], string2 [10];
      int i, j;
      printf("\nstring 1: ");
      gets(string1);
      printf("\nNstring2 : ");
      gets(string2);
      i = 0;
      while (string1[i] != 0)
      {
          j = 0;
          while (string1[i++] == string2[j++] &amp;&amp;string1[i-1] != 0 &amp;&amp; string2[j-1] != 0)
              ;//i dont know what it mean and why we can put ;after while loop
          if (string1[i-1] != 0 &amp;&amp; string2[j-1] == 0)
          printf("\nfound at position %d", i-j);
      }
      getch();
  }
  </code></pre>
  
  <p>why we can put <code>;</code> after while loop , anyone can help?</p>