How to convert utf8 to gbk encoding in php

With the development of the Internet, cross-language communication and internationalization have become more and more common needs. Data transfer and processing between websites is also becoming increasingly complex due to different encoding methods. In this process, some old encoding methods are still used, such as GBK encoding. In order to be compatible with various encoding methods, PHP provides some built-in functions for encoding conversion. This article will introduce how to convert UTF8 encoding into GBK encoding.

1. Understand encoding

First of all, we need to understand what utf8 and GBK encoding are.

utf8 is a variable-length character encoding, part of the International Organization for Standardization ISO, and an implementation of the Unicode character set. UTF8 encoding can accommodate all Unicode characters. It uses 1-4 bytes to describe a character and is currently the most widely used encoding method. UTF8 encoding can be used on various file formats and transmission protocols.

GBK encoding is a double-byte encoding suitable for Chinese characters and other Asian language character sets. GBK encoding is widely used in mainland China and is currently one of the most common encoding methods. GBK encoding also supports ASCII characters such as English and numbers.

2. PHP encoding conversion function

In PHP, there are some built-in functions that can convert between different encodings, including mb_convert_encoding(), iconv() and mb_convert_variables() functions.

mb_convert_encoding() function is a commonly used function in PHP for string encoding conversion. It converts a string's encoding from one encoding to another. The syntax of this function is as follows:

string mb_convert_encoding (string $str, string $to_encoding [, mixed $from_encoding = mb_internal_encoding()])

where $str is the string to be converted ; $to_encoding is the converted encoding method; $from_encoding is the original encoding method, and the default value is mb_internal_encoding().

iconv() function can also implement encoding conversion. It supports more encoding methods and is more stable in some old environments. The syntax of the iconv() function is as follows:

string iconv (string $in_charset, string $out_charset, string $str)

Among them, $in_charset is the original encoding; $out_charset is the target encoding; $ str is the string to be converted.

It is possible to convert from one encoding to another with the mb_convert_variables() function. This function is more convenient when dealing with the conversion of multiple strings, because it can convert multiple strings at the same time without going through a foreach or while loop. The syntax of this function is as follows:

mb_convert_variables(string $to_encoding, mixed $from_encoding, mixed &$var1 [, mixed &$var2 [, mixed &$... ]])

where , $to_encoding is the target encoding; $from_encoding is the original encoding; $var1 is the string variable to be converted to encoding; $var2, $... are other string variables to be converted to encoding.

3. Convert utf8 to GBK encoding

Now, let’s write code to convert utf8 encoding to GBK encoding. First, we can use the built-in function mb_convert_encoding() to convert the encoding:

$str = "utf8编码转换为GBK编码";
$gbk_str = mb_convert_encoding($str, "GBK", "utf8");
echo $gbk_str;

The result of code execution is:

utf8编码转换为GBK编码

We can see that the string in $str is converted to GBK encoding.

In addition, we can also use the iconv() function to perform encoding conversion:

$str = "utf8编码转换为GBK编码";
$gbk_str = iconv("utf8","GBK//IGNORE",$str);
echo $gbk_str;

The execution result of this code is also:

utf8编码转换为GBK编码

Finally, let’s take a look How to use the mb_convert_variables() function to convert the encoding of multiple variables:

$str1 = "utf8编码转换为GBK编码";
$str2 = "php编程入门";
mb_convert_variables("GBK", "utf8", $str1, $str2);
echo $str1."
".$str2;

The execution result of the code is:

utf8编码转换为GBK编码
php编程入门

We can see that the strings in $str1 and $str2 are both Converted to GBK encoding.

4. Summary

Through the introduction of this article, we have understood the concepts of utf8 and GBK encoding, and learned how to use built-in functions to convert encodings in PHP. In actual development, it is very important to choose the appropriate coding method for data processing according to specific needs and environment. I hope the introduction in this article can provide some help to readers.

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