title: how do char pointers work with while loop
body: <p>In the while loop when <code>*s</code> is mentioned it means the value at the address contained in <code>s</code>, so in the first case, the value will be 'a', </p>
  
  <p>my question is how will while loop checks it, does it checks the ASCII value of the characters to check the condition is true or false ..are some other way?</p>
  
  <pre><code>main()
  {
     char str[] = "abcd" ;
     char *s = str;
     while(*s)
         printf ("%c",*s++) ;
  }
  </code></pre>