1. string strstr($pattern,$needle,[true/false])

 

 2. str_replace($target,$instead,$str,[count]);str_ireplace

 

 3.string substr('abcdef',-1,1);返回字符串的子字符串

 4.array explode(" ","piece1 piece2 piece3"); 分割成数组

 5.strpos strchr strrchr

 6 str_split()