var arr1 = ["1", "2", "3"];        
   var arr2 = [1, "f", "g", 3];         
   var arr3 = [];       
     for (var s in arr1) {  
          for (var x in arr2) {           
             if (arr1[s] == arr2[x]) {  
                 arr3.push(arr1[s]);      
             }
         }
     }    

      alert("相同的是："+arr3);
      var a = [1, 2, 3, 4, 5, 6, 7];   
      var b = [1, 2, 5];        
      var c = [];        
      var tmp = a.concat(b);      
      var o = {};        

     for (var s = 0; s < tmp.length; s++) {       

        (tmp[s] in o) ? o[tmp[s]]++ : o[tmp[s]] = 1;      

     }       

    for (x in o) if (o[x] == 1) c.push(x);            
        alert("不相同的是："+c);