Solution to the Hackerrank Algorithm for Couting Sort 1

countingSort.js

function countingSort(arr) {
  // Create new Array to hold sorted values
  const results = new Array(10).fill(0);

  // Loop through array and add values to results array
  for (let i = 0; i < arr.length; i++) {
    const currentNum = parseInt(arr[i], 10);
    if (typeof results[i] === undefined) {
      results[i] = 0;
    }
    if (typeof results[currentNum] === undefined) {
      results[currentNum] = 1;
    } else {
      results[currentNum] += 1;
    }
  }

  return results;
}

const test1 = countingSort([1, 1, 2, 2, 3]);

console.log(test1);