PHP字符截取函数,兼容各类gbk,utf-8编码_php教程_php教程

在PHP中字符截取函数substr只能截取全英文才不会出现乱码如果里面有中文肯定是无法截取的,下面小编来给大家介绍两个兼容各类gbk,utf-8编码字符串截取函数,实例代码如下:

function CsubStrPro($str, $start, $length, $charset = "utf-8", $suffix = false)

{

if (function_exists ( "mb_substr" ))

return mb_substr ( $str, $start, $length, $charset );

$re ['utf-8'] = "/[x01-x7f]|[xc2-xdf][x80-xbf]|[xe0-xef][x80-xbf]{2}|[xf0-xff][x80-xbf]{3}/";

$re ['gb2312'] = "/[x01-x7f]|[xb0-xf7][xa0-xfe]/";

$re ['gbk'] = "/[x01-x7f]|[x81-xfe][x40-xfe]/";

$re ['big5'] = "/[x01-x7f]|[x81-xfe]([x40-x7e]|xa1-xfe])/";

preg_match_all ( $re [$charset], $str, $match );

$slice = join ( "", array_slice ( $match [0], $start, $length ) );

if ($suffix)

return $slice . "…";

return $slice;

}

实例代码二:

function subString_UTF8($str, $start, $lenth)

{

$len = strlen($str);

$r = array();

$n = 0;

$m = 0;

for($i = 0; $i < $len; $i++) {

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

$a = base_convert(ord($x), 10, 2);

$a = substr('00000000'.$a, -8);

if ($n < $start){

if (substr($a, 0, 1) == 0) {

}elseif (substr($a, 0, 3) == 110) {

$i += 1;

}elseif (substr($a, 0, 4) == 1110) {

$i += 2;

}

$n++;

}else{

if (substr($a, 0, 1) == 0) {

$r[ ] = substr($str, $i, 1);

}elseif (substr($a, 0, 3) == 110) {

$r[ ] = substr($str, $i, 2);

$i += 1;

}elseif (substr($a, 0, 4) == 1110) {

$r[ ] = substr($str, $i, 3);

$i += 2;

}else{

$r[ ] = '';

}

if (++$m >= $lenth){

break;

}

return $r;

} // End subString_UTF8;

// End String

由于此函数返回的是一个数组,因此要配合join函数来显示字符串:join('',subString_UTF8($str, $start, $lenth));,在页面显示的时候还可以在此语句后面连一个"..."

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