title: How to give alternating table rows different background colors using PHP
body: <p>I have a table of data that is generated dynamically based on the contents stored in a mysql database.</p>
  
  <p>This is how my code looks:</p>
  
  <pre><code>&lt;table border="1"&gt;
      &lt;tr&gt;
          &lt;th&gt;Name&lt;/th&gt;
          &lt;th&gt;Description&lt;/th&gt;
          &lt;th&gt;URL&lt;/th&gt;
      &lt;/tr&gt;
      &lt;?php
          $query = mysql_query("SELECT * FROM categories");
          while ($row = mysql_fetch_assoc($query)) {
              $catName = $row['name'];
              $catDes = $row['description'];
              $catUrl = $row['url'];
  
              echo "&lt;tr class=''&gt;";
              echo "&lt;td&gt;$catName&lt;/td&gt;";
              echo "&lt;td&gt;$catDes&lt;/td&gt;";
              echo "&lt;td&gt;$catUrl&lt;/td&gt;";
              echo "&lt;/tr&gt;";
          }
      ?&gt;
  &lt;/table&gt;
  </code></pre>
  
  <p>Now if the table was static, then I would just assign each alternating table row one of 2 styles in repeated order:</p>
  
  <pre><code>.whiteBackground { background-color: #fff; }
  .grayBackground { background-color: #ccc; }
  </code></pre>
  
  <p>and that would be the end of that. However since the table rows are dynamically generated, how can I achieve this?</p>