Loop.js is a very small, but powerful, utility for looping over array-like objects. It enables the classical functional patterns like map, filter, fold and find with a single simple operation and features the ability to break out of the loop early.
var result = loop(arrayLike, defaultResult, function(lo){
var theCurrentItem = lo.item;
var theCurrentIndex = lo.index();
//Starts with the value of the defaultResult parameter, returned at end of iteration
var theResultSoFar = lo.result;
var isLastItemInTheArray = lo.isLast();
lo.stop(); //break out of loop
});