(PHP 4 >= 4.3.0, PHP 5)
mb_substr_count — Count the number of substring occurrences
Counts the number of times the needle substring occurs in the haystack string.
The number of times the needle substring occurs in the haystack string.
Example #1 mb_substr_count() example
<?php
echo mb_substr_count("This is a test", "is"); // prints out 2
?>