How to intercept strings with php without garbled characters

In PHP, if the substr() function intercepts a Chinese string, garbled characters may appear. This is because the number of bytes occupied by one byte in Chinese and Western characters is different.

The length parameter of substr is calculated in bytes. When encoding in GB2312, a Chinese character occupies 2 bytes and an English character occupies 1 byte; while in GB2312 encoding, In UTF-8 encoding, a Chinese character may occupy 2 or 3 bytes, and English or half-width punctuation characters may occupy 1 byte. (Recommended learning: PHP programming from entry to proficiency)

Directly using the PHP function substr to intercept Chinese characters may cause garbled characters, mainly because substr may forcibly convert a Chinese character "Saw" in half. Solution:

1. Use the mb_substr interception of the mbstring extension library to avoid garbled characters.

2. Write the interception function yourself, but the efficiency is not as high as using the mbstring extension library.

3. If it is just to output the intercepted string, it can be implemented in the following way: substr($str, 0, 30).chr(0).

The substr() function can split text, but if the text to be split includes Chinese characters, you will often encounter problems. In this case, you can use the mb_substr()/mb_strcut function.

The usage of mb_substr()/mb_strcut is similar to substr(), except that one more parameter needs to be added at the end of mb_substr()/mb_strcut to set the encoding of the string, but most servers do not open php_mbstring. dll, you need to open php_mbstring.dll in php.ini.

For example:

<?php
echo mb_substr(&#39;这样一来我的字符串就不会有乱码^_^&#39;, 0, 7, &#39;utf-8&#39;);
?>

Output: This way my words

<?php
echo mb_strcut(&#39;这样一来我的字符串就不会有乱码^_^&#39;, 0, 7, &#39;utf-8&#39;);
?>

Output: This way一

As can be seen from the above example, mb_substr splits characters by words, while mb_strcut splits characters by bytes, but neither will produce half a character.

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