Php Chinese character string truncation garbled problem solution

The problem of Chinese truncation garbled characters is generally Chinese text mixing more, if you intercept English will not be a problem, Chinese will have, the main reason is: String Encoding for UTF-8, a Chinese character

The problem of Chinese truncation garbled characters is generally Chinese text mixing more, if you intercept English will not be a problem, Chinese will have, the main reason is: String Encoding for UTF-8, A Chinese character occupies three bytes while a string is encoded as GB2312. a Chinese character occupies two bytes. let's take a look at the example.

The string is encoded as GB2312, and a Chinese character occupies two bytes. the code is as follows:

1. Public static function chinesesubstr ($ str, $ start, $ len) {// $ str indicates the string, $ start indicates the start position of the string, and $ len indicates the string length.
2. $ Strlen = $ start + $ len; // use $ strlen to store the total length of the string, that is, from the start position of the string to the total length of the string
3. For ($ I = $ start; $ I <$ strlen ;){
4. If (ord (substr ($ str, $ I, 1)> 0xa0) {// if the ASCII order value of the first byte in the string is greater than 0xa0, it indicates Chinese characters
5. $ Tmpstr. = substr ($ str, $ I, 2); // Extract two characters each time and assign them to the variable $ tmpstr, which is equal to one Chinese character.
6. $ I = $ I + 2; // variable auto-Increment 2
7. } Else {
8. $ Tmpstr. = substr ($ str, $ I, 1); // if it is not a Chinese character, a character is taken out each time and assigned to the variable $ tmpstr
9. $ I ++;
10. }
11. }
12. Return $ tmpstr; // return a string
13. }

Character string encoded as UTF-8, a Chinese character occupies three bytes, the code is as follows:

1. Public static function chinesesubstr ($ str, $ start, $ len) {// $ str indicates the string, $ start indicates the start position of the string, and $ len indicates the string length.
2. $ Strlen = $ start + $ len; // use $ strlen to store the total length of the string, that is, from the start position of the string to the total length of the string
3. For ($ I = $ start; $ I <$ strlen ;){
4. If (ord (substr ($ str, $ I, 1)> 0xa0) {// if the ASCII order value of the first byte in the string is greater than 0xa0, it indicates Chinese characters
5. $ Tmpstr. = substr ($ str, $ I, 3); // each time, three characters are taken out and assigned to the variable $ tmpstr, which is equal to a Chinese character.
6. $ I = $ I + 3; // variable auto-Increment 3
7. } Else {
8. $ Tmpstr. = substr ($ str, $ I, 1); // if it is not a Chinese character, a character is taken out each time and assigned to the variable $ tmpstr
9. $ I ++;
10. }
11. }
12. Return $ tmpstr; // return a string
13. }

Although this problem has been solved above, it is relatively troublesome to pay attention to the encoding problem. The following describes a solution that no matter what encoding is required. the code is as follows:

1. /**
2. * Chinese character truncation functions supported by Utf-8 and gb2312
3. * Cut_str (string, truncation length, start length, encoding );
4. * The default encoding format is UTF-8.
5. * The default start length is 0.
6. */
7. Function cut_str ($ string, $ sublen, $ start = 0, $ code = 'utf-8 ')
8. {
9. If ($ code = 'utf-8 ')
10. {
11. $ 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]/";
12. Preg_match_all ($ pa, $ string, $ t_string );
13. If (count ($ t_string [0])-$ start> $ sublen) return join ('', array_slice ($ t_string [0], $ start, $ sublen )). "... ";
14. Return join ('', array_slice ($ t_string [0], $ start, $ sublen ));
15. }
16. Else
17. {
18. $ Start = $ start * 2;
19. $ Sublen = $ sublen * 2;
20. $ Strlen = strlen ($ string );
21. $ Tmpstr = '';
22. For ($ I = 0; $ I <$ strlen; $ I ++)
23. {
24. If ($ I >=$ start & $ I <($ start + $ sublen ))
25. {
26. If (ord (substr ($ string, $ I, 1)> 129)
27. {
28. $ Tmpstr. = substr ($ string, $ I, 2 );
29. }
30. Else
31. {
32. $ Tmpstr. = substr ($ string, $ I, 1 );
33. }
34. }
35. If (ord (substr ($ string, $ I, 1)> 129) $ I ++;
36. }
37. If (strlen ($ tmpstr) <$ strlen) $ tmpstr. = "... ";
38. Return $ tmpstr;
39. }
40. }