How to replace php keywords

php keyword replacement method: 1. Use the "preg_replace" function to realize the keyword replacement function, and you can control the number of substitutions; 2. Use the "substr_replace" function to realize the keyword replacement, but only One replacement.

Recommended: "PHP Tutorial"

php keyword replacement

(1) Use the preg_replace function to implement this function. Because the preg_replace function itself can control the number of replacements, I thought of it from the beginning. The specific implementation method is as follows:

//可以实现替换次数的控制，不仅限于只替换一次，比如$limit为2的时候表示一个词出现很多吃的时候仅替换2次，-1表示全部替换。$search 和 $replace 都可以是字符串或者数组，但必须对应 function str_replace_limit($search,$replace,$content,$limit=-1){ if(is_array($search)){ foreach ($search as $k=>$v){ $search[$k]='`'.preg_quote($search[$k],'`').'`'; } }else{ $search='`'.preg_quote($search,'`').'`'; } //把图片描述去掉 $content=preg_replace("/alt=([^ >]+)/is",'',$content); return preg_replace($search,$replace,$content,$limit); }

(2) Use substr_replace Function to implement, but here only one replacement can be achieved

//首先找到关键字所在位置，然后使用 substr_replace（系统函数）进行替换操作 function str_replace_once($search,$replace,$content){ //把图片描述去掉 $content=preg_replace("/alt=([^ >]+)/is",'',$content); $pos=strpos($content,$search); if($pos===false){ return $haystack; } return substr_replace($content,$replace,$pos,strlen($search)); }

The above is the detailed content of How to replace php keywords. For more information, please follow other related articles on the PHP Chinese website!