Get the item that appears the most times in an array

Question

var store = [\'1\',\'2\',\'2\',\'3\',\'4\'];

I want to find out that 2 appear the most in the array. How do I go about doing that?

Answer 1

If the array is sorted this should work:

function popular(array) { 
   if (array.length == 0) return [null, 0];
   var n = max = 1, maxNum = array[0], pv, cv;

   for(var i = 0; i < array.length; i++, pv = array[i-1], cv = array[i]) {
      if (pv == cv) { 
        if (++n >= max) {
           max = n; maxNum = cv;
        }
      } else n = 1;
   }

   return [maxNum, max];
};

popular([1,2,2,3,4,9,9,9,9,1,1])
[9, 4]

popular([1,2,2,3,4,9,9,9,9,1,1,10,10,10,10,10])
[10, 5]