PHP – mb_strrpos() function

The mb_strrpos() function in PHP is used to find the position of the last occurrence of a string in another string. This function performs the multibyte safe strrpos() operation based on the number of characters and is particularly useful when working with multibyte character encodings like UTF-8.

Syntax

int mb_strrpos(
   string $haystack,
   string $needle,
   int $offset = 0,
   string $encoding = null
)

Parameters

mb_strrpos() accepts the following four parameters −

• $haystack − The string to search in.

• $needle − The string to search for in the haystack.

• $offset − Search offset. If negative, the search starts from this many characters from the end of the string.

• $encoding − Character encoding to use. If omitted, the internal character encoding is used.

Return Value

mb_strrpos() returns the numeric position of the last occurrence of the needle in the haystack string. If the needle is not found, it returns false.

Example 1

Basic usage to find the last occurrence of a substring −

<?php
   mb_internal_encoding("UTF-8");
   
   $text = "Hello World Hello";
   $position = mb_strrpos($text, "Hello");
   
   var_dump($position);
?>

int(12)

Example 2

Searching with multibyte characters −

<?php
   mb_internal_encoding("UTF-8");
   
   $text = "????????????";
   $position = mb_strrpos($text, "?????");
   
   var_dump($position);
?>

int(6)

Example 3

Using offset parameter −

<?php
   mb_internal_encoding("UTF-8");
   
   $text = "Hello World Hello";
   $position = mb_strrpos($text, "Hello", -10);
   
   var_dump($position);
?>

int(0)

Conclusion

The mb_strrpos() function is essential for finding the last occurrence of substrings in multibyte strings. It properly handles Unicode characters and provides reliable string searching capabilities for international applications.