Remember the relationship between Chinese and English byte length and encoding in PHP and Java

1.PHP

PHP is actually the same as C language, uses ASCII, One char occupies 1 byte, in GBK encoding, one English occupies 1 byte, and one Chinese occupies 2 bytes. However, under UTF-8 encoding, an English character still occupies 1 byte, but a Chinese character occupies 3-4 bytes (usually 3 bytes). This usually allows you to obtain the word length of the string or String interception causes trouble. For example:

<?php
$str = "我爱你Iloveyou";
echo strlen($str); //utf8下是17，GBK下是14，但如果问你$str的字长是多少，或者让你显示前6个字，其余省略号表示，怎么办？
?>

2.Java

A char in java is 2 bytes. Java uses Unicode, and 2 bytes are used to represent a character. The Unicode encoding of a Chinese or English character occupies 2 bytes, but if other encoding methods are used, the number of bytes occupied by a character is different. For example:

public class Test {
    public static void main(String[] args){
        String str = "我们aaaaa";
        int byte_len = str.getBytes().length;
        int len = str.length();
        System.out.println("字节长度为：" + byte_len);
        System.out.println("字符长度为：" + len);
    }
}