binary-search.js

/* Binary Search Implementation in JavaScript */

function binarySearch(arr, item) {
	var low = 0,
		high = arr.length - 1,
		mid, found = false;

	while (low <= high) {
		mid = Math.floor((low + high) / 2); //Midpoint of the Search Space

		if (arr[mid] === item) { //Found the element
			found = true;
			break;
		} else {
			if (item < arr[mid]) { //Need to search in the left half of the search space
				high = mid - 1;
			} else { //Need to search in the right half of the search space
				low = mid + 1;
			}
		}
	}

	return found;
}


/************ Testing Binary Search Implementation ***************/

// This list must be sorted. If it is not given as sorted, sort it first, then call the binarySearch method
var testList = [0, 1, 2, 8, 13, 17, 19, 32, 42];
console.log(binarySearch(testList, 3));
console.log(binarySearch(testList, 13));