[bobbylarrybobby]

The point of these functions is to give names to common operations that happen in loops so that you can read the code more quickly. Map: we're transforming values. Filter: we're dropping values. Reduce: we're accumulating. Yes you can write these out explicitly in a loop but then you actually have to read all of the associated noise to grok what's happening.

In addition, the method-based approach scopes the variables to each individual call so there's no risk of, say, transforming the loop variable but then accidentally filtering based on the original instead of the transformed.