PHP代码实现强制换行

 1 //$str:输入字符串；
 2 //$num:超过多少个字符后进行换行(换行后每行的最大字符数)
 3 function forceBlackString($str, $num){
 4     if(strlen($str)>$num){
 5         $tempStr = substr($str,0,$num);
 6         $lastStr = substr($str,$num);
 7         $str = $tempStr.‘<br>‘.$lastStr;
 8     }
 9     return $str;
10 }

 1 function forceBlackStringEx($str, $num){
 2         //1.先算出字符串总长度
 3     $str_length = strlen($str);
 4         //2.计算最多能够分成几个子字符串
 5     $strNum = $str_length/$num>0 ? ($str_length/$num) : ($str_length/$num)+1;
 6     $resultStr = ‘‘;
 7         //3.循环截取
 8     for($i=0; $i<$strNum; $i++){
 9         $resultStr .= ‘<br>‘.substr($str, $i*$num,$num);
10     }
11         //4.去掉结果字符串开头多余的 <br>，长度位4
12     $resultStr = substr($resultStr, 4);
13     return $resultStr;
14 }