var arr1=[3, 'a', 'a', 'a', 2, 3, 'a', 3, 'a', 2, 4, 9, 3];  
var mf = 1;  
var m = 0;  
var item;  
for (var i=0; i<arr1.length; i++)  
{  
        for (var j=i; j<arr1.length; j++)  
        {  
                if (arr1[i] == arr1[j])  
                 m++;  
                if (mf<m)  
                {  
                  mf=m;   
                  item = arr1[i];  
                }  
        }  
        m=0;  
}  
console.log(item+" ( " +mf +" times ) ") ;  