PHP detects whether it is utf-8 or gb2312 encoding_PHP tutorial

There are many ways to detect string encoding in PHP. The most commonly used one is to directly use the mb_detect_encoding function, but there is a more advanced way to use the ASCII value of the character to judge.

Example 1

1. Method 1

The code is as follows

代码如下

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function is_utf8($str) { $c=0; $b=0; $bits=0; $len=strlen($str); for($i=0; $i<$len; $i++){ $c=ord($str[$i]); if($c > 128){ if(($c >= 254)) return false; elseif($c >= 252) $bits=6; elseif($c >= 248) $bits=5; elseif($c >= 240) $bits=4; elseif($c >= 224) $bits=3; elseif($c >= 192) $bits=2; else return false; if(($i+$bits) > $len) return false; while($bits > 1){ $i++; $b=ord($str[$i]); if($b < 128 || $b > 191) return false; $bits--; } } } return true; }

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代码如下	复制代码
function mb_is_utf8($string)   {       return mb_detect_encoding()($string, 'UTF-8') === 'UTF-8';//新发现   }

function is_utf8($str)
{
$c=0; $b=0;
$bits=0;
$len=strlen($str);
for($i=0; $i<$len; $i++){
$c=ord($str[$i]);
if($c > 128){
if(($c >= 254)) return false;
elseif($c >= 252) $bits=6;
elseif($c >= 248) $bits=5;
elseif($c >= 240) $bits=4;
elseif($c >= 224) $bits=3;
elseif($c >= 192) $bits=2;
else return false;
if(($i+$bits) > $len) return false;
while($bits > 1){
$i++;
$b=ord($str[$i]);
if($b < 128 || $b > 191) return false;
$bits--;
}
}
}
return true;
}

代码如下	复制代码
function preg_is_utf8($string)   {       return preg_match('/^.*$/u', $string) > 0;//preg_match('/^./u', $string)   }

The code is as follows

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function mb_is_utf8($string)
{
Return mb_detect_encoding()($string, 'UTF-8') === 'UTF-8';//New discovery
} 2. Method 2

The code is as follows

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function preg_is_utf8($string) { Return preg_match('/^.*$/u', $string) > 0;//preg_match('/^./u', $string) } http://www.bkjia.com/PHPjc/632796.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/632796.htmlTechArticleThere are many ways to detect string encoding in php. The most commonly used one is to directly use the mb_detect_encoding function, but there are still A more advanced way is to use the ASCII value of the character to judge. ...