PHP - 从字符串中删除重复的元素（<hr>）

Question

I have a string that shows each post then a <hr> element at the end of a post. But I have it so if you delete a post it shows leaves the <hr> element there so I need a script that will detect if there is more than one <hr> element and narrow it down so that it will only be left with one below each post.

Is there any chance that it is possible to do???

here is what it looks like to me:

post text post text post text post text post text 
<hr>
post text post text post text post text post text post text 
<hr>
<hr>
<hr>
<hr>
<hr>
<hr>
<hr>
<hr>
post text post text post text 
<hr>
<hr>
post text post text post text post text 
<hr>

And I need it to be like:

post text post text post text post text post text 
<hr>
post text post text post text post text post text post text 
<hr>
post text post text post text 
<hr>
post text post text post text post text 

Answer 1

• i'm using an explode <hr> here
• then filtering out the empty elements
• and then simply re-imploding with <hr>
• probably more expensive then a preg_replace()

PHP:

<?php

$content = <<<STR
post text post text post text post text post textA
<hr>
post text post text post text post text post text post textB
<hr>
<hr>
<hr>
<hr>
<hr>
<hr>
<hr>
<hr>
post text post text post textC
<hr>
<hr>
post text post text post text post textD
STR;

function remove_duplicate_hr_tags($string)
{
    $lines             = explode('<hr>', $string);
    $trimmedArray      = array_map('trim', $lines);
    $emptyRemovedArray = array_filter($trimmedArray);
    $content           = implode("
<hr>
", $emptyRemovedArray);

    return $content;
}

echo remove_duplicate_hr_tags($content);

Output

post text post text post text post text post textA
<hr>
post text post text post text post text post text post textB
<hr>
post text post text post textC
<hr>
post text post text post text post textD