Summary of the use of the iconv function for character set conversion in PHP, character set conversion iconv

Summary of the use of the iconv function for character set conversion in PHP, character set conversion iconv_PHP tutorial

WBOY

Release： 2016-07-13 10:17:28

Original

908 people have browsed it

A summary of the use of the character set conversion iconv function in php, character set conversion iconv

iconv function library can complete conversion between various character sets and is an indispensable basic function library in PHP programming.

is used as follows:

Copy code The code is as follows:

$string = "Welcome to Bangke Home!";
iconv("utf8","gbk",$string)//Convert the string encoding from utf8 to gbk;

expands as follows:

Copy code The code is as follows:

echo $str= 'Welcome to Bangke Home!';
echo '
';
echo iconv('GB2312', 'UTF-8', $str); //Convert the string encoding from GB2312 to UTF-8
echo '
';
echo iconv_substr($str, 1, 1, 'UTF-8'); //Truncate by the number of characters instead of bytes
print_r(iconv_get_encoding()); //Get the current page encoding information
echo iconv_strlen($str, 'UTF-8'); //Get the string length of the set encoding
//This is also used
$content = iconv("UTF-8","gbk//TRANSLIT",$content);

Remarks:

1. iconv is not the default function of PHP, and it is also a module installed by default. It needs to be installed before it can be used.

If it is windows2000+php, you can modify the php.ini file and remove the ";" before extension=php_iconv.dll. At the same time, you need to copy the iconv.dll in your original php installation file to your winnt/ Under system32 (if your dll points to this directory, I did not do this step locally)
In the Linux environment, use static installation and add an additional item --with-iconv when configure. The iconv item can be seen in phpinfo. (Linux7.3+Apache4.06+php4.3.2);

This concludes the introduction to iconv in php

2. Use the iconv function to convert the captured utf-8 encoded page into gb2312. I found that only by using the iconv function to transcode the captured data, the data will be less for no reason. The reason is this:

Copy code The code is as follows:

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

Note: In addition to specifying the encoding to be converted to, the second parameter can also add two suffixes: //TRANSLIT and //IGNORE, where //TRANSLIT will automatically convert characters that cannot be directly converted into one or more Approximate characters, //IGNORE will ignore characters that cannot be converted, and the default effect is to truncate from the first illegal character. If it is truncated, of course there will be less;

You can modify iconv("UTF-8","GB2312//IGNORE",$string) like this, which will ignore characters that cannot be converted;

Additional:

Introduction to mb_convert_encoding and iconv functions in PHP

The mb_convert_encoding function is used to convert encoding, similar to the iconv function.

English generally does not have encoding problems, only Chinese data will have this problem. For example, when you use Zend Studio or Editplus to write a program, you use gbk encoding. If the data needs to be entered into the database, and the database encoding is utf8, then the data must be encoded and converted, otherwise it will become garbled when entering the database. .

For the usage of mb_convert_encoding, please see the official website:

http://cn.php.net/manual/zh/function.mb-convert-encoding.php

Make a GBK To UTF-8

Copy code The code is as follows:

header("content-Type: text/html; charset=Utf-8"); //Set the character encoding to utp-8
echo mb_convert_encoding("My", "UTF-8", "GBK");
?>

Another GB2312 To Big5

Copy code The code is as follows:

header("content-Type: text/html; charset=big5");
echo mb_convert_encoding("Friend", "big5", "GB2312");
?>

However, to use the above function, you need to install it but you need to enable the mbstring extension library first. The principle is still the same, modify php.ini.
Another function iconv in PHP is also used to convert string encoding, and its function is similar to the above function.

There are some detailed examples below:

Copy code The code is as follows:

iconv — Convert string to requested character encoding
(PHP 4 >= 4.0.5, PHP 5)
mb_convert_encoding — Convert character encoding
(PHP 4 >= 4.0.6, PHP 5)

Usage:

string mb_convert_encoding ( string str, string to_encoding [, mixed from_encoding] )

You need to enable the mbstring extension library first, and remove the ; in front of extension=php_mbstring.dll in php.ini
mb_convert_encoding can specify multiple input encodings, and it will automatically identify it based on the content. However, the execution efficiency is much worse than iconv, so why do we need to explain this mb_convert_encoding() function? The answer is as follows:

It was found that iconv would make an error when converting the character "-" to gb2312. Without the ignore parameter, all strings following this character cannot be saved. No matter what, this "-" cannot be converted successfully and cannot be output. In addition, mb_convert_encoding does not have this bug.

In general, use iconv. Only use the mb_convert_encoding function when you are unable to determine what the original encoding is, or when iconv cannot be displayed normally after conversion.