Php implements Chinese character string truncation without garbled characters

The key point is to determine whether the string to be intercepted is a Chinese or English character. it can be determined by ord (substr ($ str, $ start, 1) & gt; 0xa0, if the value is greater than, it is in Chinese; otherwise, it is in English. The implementation code is as follows:

What you need to know on the homepage:
1. Chinese characters occupy 2 bytes in gbk encoding and 3 bytes in UTF-8 encoding.

2. the ord () function returns the ASCII value of the first character of the string.

3. the ASCII value of Chinese characters is greater than 0xa0.

The key point is to determine whether the string to be intercepted is a Chinese character or an English character. use ord (substr ($ str, $ start, 1)> 0xa0 to determine whether it is a Chinese character if it is greater than 0, otherwise, it is in English. The implementation code is as follows:

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0xa0) {$ pos + = $ bite; // if it is a Chinese character, the location is added with the noon character length;} else {$ pos + = 1 ;}} if ($ length = "") {returnsubstr ($ str, $ pos); // if $ length is empty, from the beginning to the last one} else {if ($ length <0) {$ length = 0 ;}$ string = ""; for ($ I = 1; $ I <= $ length; $ I ++) {if (ord (substr ($ str, $ pos, 1)> 0xa0) {// if it is a noon character, $ string. = substr ($ str, $ pos, $ bite); // capture $ pos + = $ bite according to the length of the noon character;} else {$ string. = substr ($ str, $ pos, 1); $ pos + = 1 ;}}return $ string ;}$ str = "a This is a Chinese character"; echomy _ Substr ($ str, 0); // output from the first to the last one. Echo" "; Echomy_substr ($ str, 0, 1); // output a; echo" "; Echomy_substr ($ str, 1, 2); // output this; echo" "; // Echo my_substr ($ str, 3); // if it is UTF-8 encoded, the last parameter is changed to 3;?>