Binary Search Algorithms with Shuffle and Range

searchAlgos.js

/*
#DATA STRUCTURES & ALGORITHMS

A) Binary Search with RANGE and Shuffle algorithms: 

-Algorithmic Steps

  1) If needle  == value in haystack, we're done. Exit.
  2) If needle < middle value in haystack, go left. Go to step 1.
  3) If needle > middle value in haystack, go right. Go to step 1.

*/

var binarySearch = function(haystack, needle) {
    //make sure haystack is sorted;
    haystack = haystack.sort(function(x, y) {
        return x - y;
    });

    var lowIndex = 0,
        highIndex = haystack.length - 1,
        middle;

    while (lowIndex <= highIndex) {

        //adjust new middle point either left or right
        middle = Math.floor((highIndex + lowIndex) / 2);

        if (needle === haystack[middle])
            return console.log('"' + needle + '"' + ' found at index: ' + middle);
        //adjust search area to the right
        else if (needle > haystack[middle])
            lowIndex = middle + 1;
        //adjust search area to the left
        else
            highIndex = middle - 1;
    }
    //otherwise not found
    return console.log('"' + needle + '"' + ' not found!');
};

//CREATE A LARGE ARRAY USING OUR 
//METHOD 1: var haystack = Array.apply(null, Array(1000)).map(function(_, index) { return index});
//METHOD 2;

var range = function(start, stop, step) {
    var arr = [];
    while (start <= stop) {
        arr.push(start);
        start += step;
    }
    return arr;
};

//use Fisher Yates shuffle to shuffle our array
Array.prototype.shuffle = function() {
    var listClone = this.slice(), //clone list
        rndPos, temp;
    for (var i = 0; i < listClone.length; i++) {
        rndPos = Math.floor(Math.random() * listClone.length);
        temp = listClone[i]; //store i value in temp array;
        listClone[i] = listClone[rndPos]; //replace i with random value
        listClone[rndPos] = temp; // replace random with origina i stored in temp;
    }
    return listClone;
};

//TESTS
//var haystack = ['a' , 'b' , 'c' , 'd', 'e' , 'f' , 'k']
var haystack = range(0, 1000, 3).shuffle();
binarySearch(haystack, 3); //"3" found at index: 1
binarySearch(haystack, 333); // "333" found at index: 111

haystack = range(0, 1000, 5).shuffle();
console.log(haystack);
binarySearch(haystack, 786); //"786" not found!
binarySearch(haystack, 785); //"785" found at index: 157

haystack = [];
binarySearch(haystack, 973465); //"973465" not found!
binarySearch(haystack, null); //"null" not found!