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:

1. function CsubStrPro($str, $start, $length, $charset = "utf-8", $suffix = false)
2. {
3. if (function_exists ( "mb_substr" ))
4. return mb_substr ( $str, $start, $length, $charset );
5. $re ['utf-8'] = "/[x01-x7f]|[xc2-xdf][x80-xbf]|[xe0-xef][x80-xbf]{2}|[xf0-xff][x80-xbf]{3}/";
6. $re ['gb2312'] = "/[x01-x7f]|[xb0-xf7][xa0-xfe]/";
7. $re ['gbk'] = "/[x01-x7f]|[x81-xfe][x40-xfe]/";
8. $re ['big5'] = "/[x01-x7f]|[x81-xfe]([x40-x7e]|xa1-xfe])/";
9. preg_match_all ( $re [$charset], $str, $match );
10. $slice = join ( "", array_slice ( $match [0], $start, $length ) );
11. if ($suffix)
12. return $slice . "…";
13. return $slice;
14. }

实例代码二:

1. function subString_UTF8($str, $start, $lenth)
2. {
3. $len = strlen($str);
4. $r = array();
5. $n = 0;
6. $m = 0;
7. for($i = 0; $i < $len; $i++) {
8. $x = substr($str, $i, 1);
9. $a = base_convert(ord($x), 10, 2);
10. $a = substr('00000000'.$a, -8);
11. if ($n < $start){
12. if (substr($a, 0, 1) == 0) {
13. }elseif (substr($a, 0, 3) == 110) {
14. $i += 1;
15. }elseif (substr($a, 0, 4) == 1110) {
16. $i += 2;
17. }
18. $n++;
19. }else{
20. if (substr($a, 0, 1) == 0) {
21. $r[ ] = substr($str, $i, 1);
22. }elseif (substr($a, 0, 3) == 110) {
23. $r[ ] = substr($str, $i, 2);
24. $i += 1;
25. }elseif (substr($a, 0, 4) == 1110) {
26. $r[ ] = substr($str, $i, 3);
27. $i += 2;
28. }else{
29. $r[ ] = '';
30. }
31. if (++$m >= $lenth){
32. break;
33. }
34. }
35. }
36. return $r;
37. } // End subString_UTF8;
38. // 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"..."