字符串A:"1,3,4,5,6,7,8,9,10,11,12,14,15,17,20,22,123,457",例如我想知道這個字符串里面是否含有"2",這時候"12","20","22"等.

1. //一代碼如下: 
2.  
3. if(in_array('2',explode(',',$str)) 
4.  
5. //二代碼如下: 
6.  
7. $str= '1,3,4,5,6,7,8,9,10,11,12,14,15,17,20,22,123,457'; 
8. if(strpos(',' . $str . ',', ',2,') !== false) 
9. {//開源代碼Vevb.com 
10.  //TODO 
11. } 
12.  
13. //三代碼如下: 
14.  
15. echo preg_match('/(?<=^|,)2(?=,|$)/','1,3,4,5,6,7,8,9,10,11,12,14,15,17,20,22,123,457');