js list to repeat

var dataList = []; // need to duplicate collections 
var res = []; // set the deduplication 
var TEM = {}; 
　　for (var I = 0; I <dataList.length; I ++) { 
	 IF ( ! JSON [dataList [I]]) { 
		 res.push (dataList [I]); 
		  TEM [dataList [I]] =. 1; 
	 } 
}