PHP实现截取字符串的通用方法
时间:2021-07-01 10:21:17
帮助过:11人阅读
- /**
- * 截取字符串
- * params $string 要截取的字符串
- * params $length: 保留长度(字符数)
- * params $dot: 多余部分显示
- **/
- function _cutstr($string, $length, $dot = ' ...') {
- if(strlen($string) <= $length) {
- return $string;
- }
- $string = str_replace(array('&', '"', '<', '>'), array('&', '"', '<', '>'), $string);
- $strcut = '';
- $n = $tn = $noc = 0;
- while($n < strlen($string)) {
- $t = ord($string[$n]);
- if($t == 9 || $t == 10 || (32 <= $t && $t <= 126)) {
- $tn = 1; $n++; $noc++;
- } elseif(194 <= $t && $t <= 223) {
- $tn = 2; $n += 2; $noc += 2;
- } elseif(224 <= $t && $t < 239) {
- $tn = 3; $n += 3; $noc += 2;
- } elseif(240 <= $t && $t <= 247) {
- $tn = 4; $n += 4; $noc += 2;
- } elseif(248 <= $t && $t <= 251) {
- $tn = 5; $n += 5; $noc += 2;
- } elseif($t == 252 || $t == 253) {
- $tn = 6; $n += 6; $noc += 2;
- } else {
- $n++;
- }
- if($noc >= $length) {
- break;
- }
- }
- if($noc > $length) {
- $n -= $tn;
- }
- $strcut = substr($string, 0, $n);
- $strcut = str_replace(array('&', '"', '<', '>'), array('&', '"', '<', '>'), $strcut);
- return $strcut.$dot;
- }
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PHP