A simple binary search function

binarysearch.js

function binarySearch(searchValue) {
    'use strict';

    var minIndex = 0;
    var maxIndex = sortedArray.length - 1;
    var currentIndex;
    var currentElement;

    while (minIndex <= maxIndex) {
        currentIndex = (minIndex + maxIndex) / 2 | 0;
        currentElement = sortedArray[currentIndex];
        
        // It's the same as the value in the middle - we can return!
        if (currentElement === searchValue)
        {
          return middleIndex;
        }
        // Is the value less than the value in the middle of the array
        if (currentElement < searchValue) {
            minIndex = currentIndex + 1;
        }
        // Is the value greater than the value in the middle of the array
        if (currentElement > searchValue) {
            maxIndex = currentIndex - 1;
        }
    }

    return -1;
}

// The array with all of our numbers
var sortedArray = [1,2,4,5,10,12,44,89,99,304];

// The value we are looking for in the array
var valueToFind = 89;

var result = binarySearch(sortedArray, valueToFind);

console.log('The index position is: ', result);