How to prevent automatic sort of Object numeric property?

Question

Why I met this problem: I tried to solve an algorithm problem and I need to return the number which appeared most of the times in an array. Like [5,4,3,2,1,1] should return

Answer 1

1. you can use Map() in javascript ES6 which will keep the order of the keys insertion.

2. just trying to solve your problem in an alternative solution, recently like to practise leetcode-like question

function solution(arr) {
  const obj = {};
  const record = {
    value: null,
    count: 0
  };

  for (let i = 0; i < arr.length; i++) {
    let current = arr[i];
    if (!obj[current]) {
      obj[current] = 0;
    }

    obj[current]++;

    if (obj[current] > record.count) {
      record.value = current;
      record.count = obj[current];
    }
  }

  console.log("mode number: ", record.value);
  console.log("mode number count: ", record.count);
}