title: About expressions on while loop
body: <p>Assume i > 0 is true.
  Why is this expression:</p>
  
  <pre><code>while(i &gt; 0) {
    printf("Hello \n);
    i--;
  };
  </code></pre>
  
  <p>equal to this expression:</p>
  
  <pre><code> while(i--) {
    printf("Hello \n");
  };
  </code></pre>