Re: Re: Trying to understand what is happening in this code

On 13-10-11 01:52 PM, Jim Giner wrote:

On 10/11/2013 11:01 AM, Nathan Grey wrote:

Hi - I am new to PHP so this is probably a very rudimentary question. I posed it over at Stack Overflow and got several responses but none of them clarified the issue for me. http://stackoverflow.com/questions/19309369/trying-to-understand-how-these-php-sections-work-together Here's the code I am trying to understand: <body>

      <h1>The first twenty Fibonacci numbers:</h1>
      <ul>
      <?php
      $first = 0;
      $second = 1;
      for ($i = 0; $i < 20; $i++) {
          ?>
          <li><?php echo $first + $second ?></li>
      <?php
          $temp = $first + $second;
          $first = $second;
          $second = $temp;

      } ?>
      </ul></body>

This code produces an unordered list of the first 20 Fibonacci numbers. I understand that HTML and PHP can be interspersed. I also understand that the PHP processor will look over the code and pick up the code that is between the opening and closing PHP tags. Here's where I am confused: 1. Can the processor really reassemble a for-loop that is broken into segments by opening and closing tags? It seems like the integrity of the loop would be broken. I would expect that the entire loop would have to be contained within a single pair of opening and closing tags for it to work. 2. Even if the processor is able to reassemble the loop seamlessly, how do the <li> tags get included in the loop since they fall outside of the PHP tags? Thanks for your help. Nathan ----------------------------- Nathan Grey

Perhaps this whole long discussion could have been prevented if you DIDN'T intersperse the php and html. Code (IMHO) is much easier to read and write when you separate the logic from the presentation. How about this? <? $ulist = "<h1>The first twenty Fibonacci numbers:</h1>"; $ulist .= "<ul>"; $first = 0; $second = 1; for ($i = 0; $i < 20; $i++) {

       $temp = $first + $second;
       $ulist.= "<li>$temp</li>";
       $first = $second;
       $second = $temp;

} $ulist .= "</ul>"; . . . finish processing . . DisplayPage($ulist); exit(); //******************** //******************** //******************** function DisplayPage($ulist) {

     $code =<<<heredocs
     (std. html startup lines)
      <body>
      .
      .
      $ulist
      .
      (rest of html, etc.)
      .
      .
      </body>
      </html>

heredocs;

      echo $code;
      return

} ?> All done with one pair of php tags. and logic and presentation separated.

But in practice, if you aren't switching in and out of PHP then it's best to not bother closing the PHP tag at the end lest you run into session issues due to an invisible trailing space on an included library. Cheers, Rob. -- E-Mail Disclaimer: Information contained in this message and any attached documents is considered confidential and legally protected. This message is intended solely for the addressee(s). Disclosure, copying, and distribution are prohibited unless authorized.