JavaScript binary search with the same API as indexOf. Performance: http://jsperf.com/binaryindexof-and-indexof

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 = (minIndex + maxIndex) / 2 | 0;
		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=(b+c)/2|0,d=this[a],d<e)b=a+1;else if(d>e)c=a-1;else return a;return-1};

@ftorre104 for some case that (mixIndex + maxIndex) becomes into NaN:

> NaN
NaN
> NaN / 2
NaN
> NaN / 2 | 0
0

just encure currentIndex is a number.