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Causes and solutions for PHP mb_substr function failure
In the process of developing or writing programs using PHP, you often encounter situations where strings need to be intercepted. PHP provides many string processing functions, among which the mb_substr function is a commonly used function for intercepting multi-byte characters. However, sometimes we will find that there is a failure when using the mb_substr function, that is, the string cannot be intercepted correctly. Next, we will discuss the reasons and solutions for the failure of the mb_substr function, and provide specific code examples.
Cause analysis:
Solution:
if(mb_detect_encoding($str, 'UTF-8,GBK,GB2312') != 'UTF-8'){ $str = mb_convert_encoding($str, 'UTF-8', 'auto'); }
$length = mb_strlen($str, 'UTF-8'); $substring = mb_substr($str, $start, $length, 'UTF-8');
$pattern = '/^.{0,10}/us'; // intercept the first 10 characters preg_match($pattern, $str, $matches); $substring = $matches[0];
Through the above solutions, we can effectively solve the problem of PHP mb_substr function failure and ensure that multi-byte characters can be accurately intercepted during string processing. In practical applications, it is necessary to flexibly use various methods and select appropriate processing methods based on specific circumstances, thereby improving the stability and reliability of the program.
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