var a = [2, 2, 2, 4, 4, 5, 2, 2, 3, 1, 2, 1, 1];

​

    var o = {},

        i = 0,

        m = {m:0,t:null},

        t = {m:0,t:null},

        len = a.length;

​

    for ( ; i < len ; i++ ) {

        o[ a[i] ] = ( o[ a[i] ] || 0 ) + 1;

    }

​

​

    for ( i in o ) {

        t = {

            m: o[i],

            i: i

        }

          console.log(t, m);

        m = m.m < t.m ? t : m

    }

​

    alert(m.i + " is the highest presented " + m.m + " times");

​