search an array with binary search algorithm - iterative & recursive approaches

binarySearch.js

// iterative approach
function binarySearch(arr, searchElement) {
 
	var minIndex = 0;
	var maxIndex = arr.length - 1;
	var currentIndex;
	var currentElement;
 
	while (minIndex <= maxIndex) {
		currentIndex = (minIndex + maxIndex) / 2 | 0;
		currentElement = arr[currentIndex];
 
		if (currentElement < searchElement) {
			minIndex = currentIndex + 1;
		}
		else if (currentElement > searchElement) {
			maxIndex = currentIndex - 1;
		}
		else {
			return currentIndex;
		}
	}
	return -1;
}


//recursive approach: http://cwestblog.com/2012/03/19/javascript-binary-search/

function binarySearch(arr, item, min, max, fnCmp) {
    if(min > max) {
      return -1;
    }
    var mid = parseInt((min + max) / 2);
    var ret = fnCmp(item, arr[mid]);
    if(ret) {
      return binarySearch(arr, item,
        ret > 0 ? mid + 1 : min,
        ret < 0 ? mid - 1 : max, fnCmp);
    }
    else if(ret == 0) {
      return mid;
    }
}

function fnExact(a, b) {
    return a < b ? -1 : a > b ? 1 : a === b ? 0 : null;
}