Most Frequent Number

/* Write a JavaScript function findMostFreqNum(arr) that finds the most frequent number in an array.
If multiple numbers appear the same maximal number of times, print the leftmost of them.
Write JS program numberFinder.js that invokes your function with the sample input data below
and prints the output at the console. */

"use strict";

function findMostFreqNum(arr) {
    if (arr.length > 1) {
        arr.sort();
        var equalsElements = 1;
        var currentEquals = 1;
        var repeatElement = arr[0];
        var i;
        for (i = 1; i < arr.length; i +=  1) {
            if (arr[i] === arr[i - 1]) {
                currentEquals += 1;
            } else {
                if (currentEquals > equalsElements) {
                    repeatElement = arr[i - 1];
                    equalsElements = currentEquals;
                }
                currentEquals = 1;
            }
        }

        if (currentEquals > equalsElements) {
            repeatElement = arr[arr.length - 1];
            equalsElements = currentEquals;
        }

        return repeatElement + ' (' + equalsElements + ' times)';
    } else if (arr.length == 1) return arr[0] + ' (1 times)';
    else return 'undefined (0 times)';
}

console.log(findMostFreqNum([4, 1, 1, 4, 2, 3, 4, 4, 1, 2, 4, 9, 3]));
console.log(findMostFreqNum([2, 1, 1, 5, 7, 1, 2, 5, 7, 3, 87, 2, 12, 634, 123, 51, 1]));
console.log(findMostFreqNum([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]));
console.log(findMostFreqNum([2.5]));
console.log(findMostFreqNum(['a', 'b', 'c', 'a', 'A', 'b', 'c', 'c', 'C']));
console.log(findMostFreqNum([]));