php有utf-8和gbk,PHP中GBK和UTF8编码处理

以下为引用的内容：

一、编码范围

1. GBK (GB2312/GB18030)

x00-xff GBK双字节编码范围

x20-x7f ASCII

xa1-xff 中文

x80-xff 中文

2. UTF-8 (Unicode)

u4e00-u9fa5 (中文)

x3130-x318F (韩文

xAC00-xD7A3 (韩文)

u0800-u4e00 (日文)

ps: 韩文是大于[u9fa5]的字符

正则例子:

PLAIN TEXT

PHP:

preg_replace("/([x80-xff])/","",$str);

preg_replace("/([u4e00-u9fa5])/","",$str);

二、代码例子

PLAIN TEXT

PHP:

//判断内容里有没有中文-GBK (PHP)

function check_is_chinese($s){

return preg_match('/[x80-xff]./', $s);

}

//获取字符串长度-GBK (PHP)

function gb_strlen($str){

$count = 0;

for($i=0; $i

$s = substr($str, $i, 1);

if (preg_match("/[x80-xff]/", $s)) ++$i;

++$count;

}

return $count;

}

//截取字符串字串-GBK (PHP)

function gb_substr($str, $len){

$count = 0;

for($i=0; $i

if($count == $len) break;

if(preg_match("/[x80-xff]/", substr($str, $i, 1))) ++$i;

++$count;

}

return substr($str, 0, $i);

}

//统计字符串长度-UTF8 (PHP)

function utf8_strlen($str) {

$count = 0;

for($i = 0; $i

$value = ord($str[$i]);

if($value> 127) {

$count++;

if($value>= 192 && $value <= 223) $i++;

elseif($value>= 224 && $value <= 239) $i = $i + 2;

elseif($value>= 240 && $value <= 247) $i = $i + 3;

else die('Not a UTF-8 compatible string');

}

$count++;

}

return $count;

}

//截取字符串-UTF8(PHP)

function utf8_substr($str,$position,$length){

$start_position = strlen($str);

$start_byte = 0;

$end_position = strlen($str);

$count = 0;

for($i = 0; $i