php 截取中英文混合字符串的方法_php实例_

 //截取想这样的字符串 a李三

 /** * * 中英混合的字符串截取 * @param unknown_type $sourcestr * @param unknown_type $cutlength */ function assoc_substr($sourcestr, $cutlength) { $returnstr = ''; $i = 0; $n = 0; $str_length = strlen ( $sourcestr ); //字符串的字节数 while ( ($n < $cutlength) and ($i <= $str_length) ) { $temp_str = substr ( $sourcestr, $i, 1 ); $ascnum = Ord ( $temp_str ); //得到字符串中第$i位字符的ascii码 if ($ascnum >= 224) {//如果ASCII位高与224， $returnstr = $returnstr . substr ( $sourcestr, $i, 3 ); //根据UTF-8编码规范，将3个连续的字符计为单个字符 $i = $i + 3; //实际Byte计为3 $n ++; //字串长度计1 } elseif ($ascnum >= 192){ //如果ASCII位高与192， $returnstr = $returnstr . substr ( $sourcestr, $i, 2 ); //根据UTF-8编码规范，将2个连续的字符计为单个字符 $i = $i + 2; //实际Byte计为2 $n ++; //字串长度计1 } elseif ($ascnum >= 65 && $ascnum <= 90) {//如果是大写字母， $returnstr = $returnstr . substr ( $sourcestr, $i, 1 ); $i = $i + 1; //实际的Byte数仍计1个 $n ++; //但考虑整体美观，大写字母计成一个高位字符 }elseif ($ascnum >= 97 && $ascnum <= 122) { $returnstr = $returnstr . substr ( $sourcestr, $i, 1 ); $i = $i + 1; //实际的Byte数仍计1个 $n ++; //但考虑整体美观，大写字母计成一个高位字符 } else {//其他情况下，半角标点符号， $returnstr = $returnstr . substr ( $sourcestr, $i, 1 ); $i = $i + 1; $n = $n + 0.5; } } return $returnstr; }