<?php function str_sub($parstr,$substr){ $par_str = strlen($parstr); #父字符串的长度 $sub_str = strlen($substr); #子字符串的长度 用于判断是否已经在父字符串里查找完毕 # 子字符串开始查找的偏移长度 大于 父字符串的长度 就表示已经查找到底部了 $num = 0; $poi = 0; #出现次数累计变量 while ( $poi < $par_str ) { // if (strpos($parstr,$substr,$poi) !== false) { # code... $poi = strpos($parstr, $substr,$poi); $poi += $sub_str; $num++; } } echo "${substr}出现次数为" . $num . "次" ; } $str = 'how are you! fine thank you,fine, may be you are right, 256, I dont think so,let me see,I can not fine'; str_sub($str,'fine'); ?>