How to truncate a string to a given length

Short answer

Take the required number of characters with mb_substr() and add an ellipsis if the string was longer. mb_strlen() checks the length:

<?php
 
$text = 'A very long article title';
$limit = 13;
 
echo mb_strlen($text) > $limit ? mb_substr($text, 0, $limit) . '…' : $text;

Output:

A very long a…

A built-in function

mb_strimwidth() truncates a string to a given width. That width includes the trim marker itself:

<?php
 
echo mb_strimwidth('A very long article title', 0, 14, '…');

Output:

A very long a…