本文章是收集了几个常用的字符串截取函数,这是解决了php中对各种编码的字符截取会乱码的问题,有需要的同学可以参考一下.

1、截取GB2312中文字符串,代码如下:

1. <?php
2. //截取中文字符串
3. function mysubstr($str, $start, $len) {
4. $tmpstr = "";
5. $strlen = $start + $len;
6. for($i = 0; $i < $strlen; $i++) {
7. if(ord(substr($str, $i, 1)) > 0xa0) {
8. $tmpstr .= substr($str, $i, 2);
9. $i++;
10. } else
11. $tmpstr .= substr($str, $i, 1);
12. }
13. return $tmpstr;
14. }
15. ?>

2. 截取utf8编码的多字节字符串,代码如下:

1. <?php
2. //截取utf8字符串
3. function utf8Substr($str, $from, $len)
4. //开源代码phpfensi.com
5. {
6. return preg_replace('#^(?:[x00-x7F]|[xC0-xFF][x80-xBF]+){0,'.$from.'}'.
7. '((?:[x00-x7F]|[xC0-xFF][x80-xBF]+){0,'.$len.'}).*#s',
8. '$1',$str);
9. }
10. ?>

3. UTF-8、GB2312都支持的汉字截取函数

1. <?php
2. /*
3. Utf-8、gb2312都支持的汉字截取函数
4. cut_str(字符串, 截取长度, 开始长度, 编码);
5. 编码默认为 utf-8
6. 开始长度默认为 0
7. */
8. function cut_str($string, $sublen, $start = 0, $code = 'UTF-8')
9. {
10. if($code == 'UTF-8')
11. {
12. $pa = "/[x01-x7f]|[xc2-xdf][x80-xbf]|xe0[xa0-xbf][x80-xbf]|[xe1-xef][x80-xbf][x80-xbf]|xf0[x90-xbf][x80-xbf][x80-xbf]|[xf1-xf7][x80-xbf][x80-xbf][x80-xbf]/";
13. preg_match_all($pa, $string, $t_string);
14. if(count($t_string[0]) - $start > $sublen) return join('', array_slice($t_string[0], $start, $sublen))."...";
15. return join('', array_slice($t_string[0], $start, $sublen));
16. }
17. else
18. {
19. $start = $start*2;
20. $sublen = $sublen*2;
21. $strlen = strlen($string);
22. $tmpstr = '';
23. for($i=0; $i< $strlen; $i++)
24. {
25. if($i>=$start && $i< ($start+$sublen))
26. {
27. if(ord(substr($string, $i, 1))>129)
28. {
29. $tmpstr.= substr($string, $i, 2);
30. }
31. else
32. {
33. $tmpstr.= substr($string, $i, 1);
34. }
35. }
36. if(ord(substr($string, $i, 1))>129) $i++;
37. }
38. if(strlen($tmpstr)< $strlen ) $tmpstr.= "...";
39. return $tmpstr;
40. }
41. }
42. $str = "abcd需要截取的字符串";
43. echo cut_str($str, 8, 0, 'gb2312');
44. ?>

4. BugFree 的字符截取函数,代码如下:

1. <?php
2. /**
3. * @package BugFree
4. * @version $Id: FunctionsMain.inc.php,v 1.32 2005/09/24 11:38:37 wwccss Exp $
5. *
6. *
7. * Return part of a string(Enhance the function substr())
8. *
9. * @author Chunsheng Wang <wwccss@263.net>
10. * @param string $String the string to cut.
11. * @param int $Length the length of returned string.
12. * @param booble $Append whether append "...": false|true
13. * @return string the cutted string.
14. */
15. function sysSubStr($String,$Length,$Append = false)
16. {
17. if (strlen($String) < = $Length )
18. {
19. return $String;
20. }
21. else
22. {
23. $I = 0;
24. while ($I < $Length)
25. {
26. $StringTMP = substr($String,$I,1);
27. if ( ord($StringTMP) >=224 )
28. {
29. $StringTMP = substr($String,$I,3);
30. $I = $I + 3;
31. }
32. elseif( ord($StringTMP) >=192 )
33. {
34. $StringTMP = substr($String,$I,2);
35. $I = $I + 2;
36. }
37. else
38. {
39. $I = $I + 1;
40. }
41. $StringLast[] = $StringTMP;
42. }
43. $StringLast = implode("",$StringLast);
44. if($Append)
45. {
46. $StringLast .= "...";
47. }
48. return $StringLast;
49. }
50. }
51. $String = "phpfensi.com-- 简单、精彩、通用";
52. $Length = "18";
53. $Append = false;
54. echo sysSubStr($String,$Length,$Append);
55. ?>