PHP mb_strlen Function Explained

In PHP, the function mb_strlen() is used to retrieve the length (number of characters) of a string, with “mb” standing for multibyte. This function counts the number of characters in a string, rather than simply counting the number of bytes. mb_strlen() is very useful when working with multibyte characters such as UTF-8 encoding.

Here is a simple example demonstrating the use of the mb_strlen() function.

<?php
$str = "你好，世界！";
$len = mb_strlen($str, 'utf-8');
echo "字符串 '$str' 的长度为 $len 个字符。";
?>

In the example above, we defined a string $str containing both Chinese and English characters, followed by using the mb_strlen() function to calculate the number of characters in the string (based on UTF-8 encoding). Finally, we output the result to the screen.

In short, the purpose of the mb_strlen() function is to get the number of characters in a string, especially useful for handling strings with multi-byte characters and ensuring the correct calculation of the string’s length.