syntax - What is the use of <<<EOD in PHP?

Question

I am implementing node to PDF using Drupal and tcpdf. In such case I am suppose to use this <<<EOD tag. If I don't use it, it throws error. I can't exactly get the purpose of <<<EOD.

Could anybody please explain the concept of this?

$html = <<<EOD
        <tr>
          <td>TEST</td>
        </tr>
EOD;

Answer 1

That is not HTML, but PHP. It is called the HEREDOC string method, and is an alternative to using quotes for writing multiline strings.

The HTML in your example will be:

    <tr>
      <td>TEST</td>
    </tr>

Read the PHP documentation that explains it.