https://lodash.com/docs#now
https://lodash.com/
Why Lodash?
Lodash makes JavaScript easier by taking the hassle out of working with arrays, numbers, objects, strings, etc. Lodash’s modular methods are great for:
- Iterating arrays, objects, & strings
- Manipulating & testing values
- Creating composite functions
http://underscorejs.org/#
Underscore is a JavaScript library that provides a whole mess of useful functional programming helpers without extending any built-in objects. It’s the answer to the question: “If I sit down in front of a blank HTML page, and want to start being productive immediately, what do I need?” … and the tie to go along with jQuery‘s tux and Backbone‘s suspenders.
Underscore provides over 100 functions that support both your favorite workaday functional helpers: map, filter, invoke — as well as more specialized goodies: function binding, javascript templating, creating quick indexes, deep equality testing, and so on.
http://www.collectionsjs.com/
These collections provide specialized alternatives to plain arrays and objects. They include the ability to observe all changes, have a common interface across every collection and work in both Node.js and the browser.
Some data structures are better suited for specific problems. The collections package gives you the freedom to experiment with different approaches, without having to change your existing usage.
Each collection implements generic methods, many already familiar from ordinary Arrays, and many new methods that will enrich your toolset.
原文：http://www.cnblogs.com/lightsong/p/7143396.html