(PHP 4 >= 4.0.6, PHP 5, PHP 7, PHP 8)
mb_strlen — Get string length
   Returns the number of characters in
   string string having character encoding
   encoding. A multi-byte character is
   counted as 1.
  
   If the encoding is unknown, an error of level
   E_WARNING is generated.
  
| Version | Description | 
|---|---|
| 8.0.0 | 
  encoding is nullable now.
  |