A function that given an array of integers, it return a map of integers that appear multiple times and the number of times it appears.

mapOfIntergers.js

const mapOfIntergers = arrayOfInts => {
  let results = {};
  for (let i = 0; i < arrayOfInts.length; i++) {
    let m = arrayOfInts[i];
    let count = arrayOfInts.filter(dupInt => dupInt === m).length;
    if (count > 1) results[m] = count;
  }
  return results;
};

console.log('mapOfIntergers', mapOfIntergers([1, 2, 3, 4, 6, 6, 7, 8, 9, 5, 2, 6, 1, 8]));