PHP: How do you determine every Nth iteration of a loop?

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I wanted to echo an image every after 3 post via XML here is my code :

<?php
// URL of the XML feed.
$feed = 'test.xml';
// How many items do we want to display?
//$display = 3;
// Check our XML file exists
if(!file_exists($feed)) {
  die('The XML file could not be found!');
}
// First, open the XML file.
$xml = simplexml_load_file($feed);
// Set the counter for counting how many items we've displayed.
$counter = 0;
// Start the loop to display each item.
foreach($xml->post as $post) {
  echo ' 
  <div style="float:left; width: 180px; margin-top:20px; margin-bottom:10px;">
 image file</a> <div class="design-sample-txt">'. $post->author.'</div></div>
';

  // Increase the counter by one.
  $counter++;
  // Check to display all the items we want to.
  if($counter >= 3) {
    echo 'image file';
    }
  //if($counter == $display) {
    // Yes. End the loop.
   // break;
  //}
  // No. Continue.
}
?>

here is a sample first 3 are correct but now it doesn't loop idgc.ca/web-design-samples-testing.php

Answers

The easiest way is to use the modulus division operator.

if ($counter % 3 == 0) {
   echo 'image file';
}

How this works: Modulus division returns the remainder. The remainder is always equal to 0 when you are at an even multiple.

There is one catch: 0 % 3 is equal to 0. This could result in unexpected results if your counter starts at 0.

Friday, August 26, 2022

waylaidwanderer-6ca2d6f11aa1

$i=0;
foreach ($x as $key=>$value)
  {
  if (fmod($i,2)) echo '<tr>';
  echo '<td>',$value,'</td>';
  if (fmod($i,2)) echo '</tr>';
  $i++;
  }

this will output TR (row) each second time

ps: i haven't tested the code, so maybe you will need to add ! sign before fmod, if it doesn't output TR on first iteration, but on second iteration in the beginning...

Tuesday, August 9, 2022

blend

$small = substr($big, 0, 100);

For String Manipulation here is a page with a lot of function that might help you in your future work.

Tuesday, August 30, 2022

k_mo

The following code will look through the two dimensions of the array and make them into a table. Regardless of what the key may be, you will get a visual representation of it. If they do have key name and not just an index, the values will be available in $key and $subkey respectively. So you have them if you need them.

The code:

$myarray = array("key1"=>array(1,2,3,4),
                 "key2"=>array(2,3,4,5),
                 "key3"=>array(3,4,5,6),
                 "key4"=>array(4,5,6,7)); //Having a key or not doesn't break it
$out  = "";
$out .= "<table>";
foreach($myarray as $key => $element){
    $out .= "<tr>";
    foreach($element as $subkey => $subelement){
        $out .= "<td>$subelement</td>";
    }
    $out .= "</tr>";
}
$out .= "</table>";

echo $out;

The result:

If you want to see the keys as headings, you could add this code after the echo "<table>"; line:

echo "<tr>";
foreach($myarray as $key => $element) echo "<td>$key</td>";
echo "</tr>";

Resulting in this:

Sunday, October 23, 2022

laginimaineb

You could use a different regex pattern delimiter character:

return preg_replace('#.*#',
    'Lorem Ipsum' .
    'More Lorem Ipsum'
    ,
    $foo);

EDIT: The delimiter character is a feature of PCRE (Perl Compatible Regular Expresssion). No PHP configuration is needed to use a different delimiter.

Regexp Quote-Like Operators

...you can use any pair of non-alphanumeric, non-whitespace characters as delimiters. This is particularly useful for matching path names that contain "/", to avoid LTS (leaning toothpick syndrome).

Quote and Quote-like Operators

Non-bracketing delimiters use the same character fore and aft, but the four sorts of ASCII brackets (round, angle, square, curly) all nest

These are all valid:

'/.*/'
'#.*#'
'{.*}' /* Note that '{.*{' would be incorrect. */

Take a look at PHP's documentation on PCRE Patterns to see a really good overview.

Friday, December 16, 2022

aamir_quraishi

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PHP: How do you determine every Nth iteration of a loop?

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