binary-search.js

/**
 * Performs a binary search on the host array. This method can either be
 * injected into Array.prototype or called with a specified scope like this:
 * binaryIndexOf.call(someArray, searchElement);
 *
 * @param {*} searchElement The item to search for within the array.
 * @return {Number} The index of the element which defaults to -1 when not found.
 */
function binaryIndexOf(searchElement) {
	'use strict';

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

	while (minIndex <= maxIndex) {
		currentIndex = Math.floor((minIndex + maxIndex) / 2);
		currentElement = this[currentIndex];

		if (currentElement < searchElement) {
			minIndex = currentIndex + 1;
		}
		else if (currentElement > searchElement) {
			maxIndex = currentIndex - 1;
		}
		else {
			return currentIndex;
		}
	}

	return -1;
}

binary-search.min.js

/**
 * Performs a binary search on the host array. This method can either be
 * injected into Array.prototype or called with a specified scope like this:
 * binaryIndexOf.call(someArray, searchElement);
 *
 * @param {*} e The item to search for within the array.
 * @return {Number} The index of the element which defaults to -1 when not found.
 */
function s(e){for(var b=0,c=this.length-1,a,d;b<=c;)if(a=Math.floor((b+c)/2),d=this[a],d<e)b=a+1;else if(d>e)c=a-1;else return a;return-1}