Binary Search

gistfile1.js

var list = [1,4,8,10,23,26,55,77,88];

var binarySearch = function(key) {
	var low = 0;
	var high = list.length - 1;

	while(low <= high) {
	  var mid = Math.floor(low + (high - low) / 2);

	  if (key < list[mid]) {
	    high = mid - 1;
	  } else if (key > list[mid]) {
	    low = mid + 1;
	  } else {
	    return mid;
	  }
	}
    return -1;
}

// Returns index of N, if not found returns -1
console.log(binarySearch(4));