(PHP 4 >= 4.0.6, PHP 5)
mb_strlen — Get string length
$str
$encoding
Gets the length of a string.
str
The string being checked for length.
encoding
encoding 参数为字符编码。如果省略，则使用内部字符编码。
Returns the number of characters in string str having character encoding encoding. A multi-byte character is counted as 1.