The preceding three chapters alluded to transformation possibilities with Lo-Dash. Whether you're working with collections, objects, or functions, a common pattern with Lo-Dash functions is transformation of the input by generating a new, albeit slightly altered, version. The idea of transforming values is central to applicative programming, where much of the code you write is a series of transformations. Beginning with this chapter, we're going to shift gears and look at transformations in more detail.

Particularly, we'll be looking at all the interesting things we can do with Lo-Dash and the map/reduce programming model. We'll start off with the basics, getting our feet wet with some basic mappings and basic reductions. As we progress through the chapter, we'll start introducing more advanced techniques to think about in terms of map/reduce with Lo-Dash.

The goal, once you've reached the end of this chapter, is to have a solid understanding of...