Learn Underscore.js!

Underscore.js is a JavaScript library which provides utility functions for common programming tasks. It is comparable to features provided by Prototype.js and the Ruby language, but opts for a functional programming design instead of extending object prototypes. For example, Underscore.js' _.each() function delegates to the host environment's native forEach implementation when present, or a compatible version when absent. The documentation refers to Underscore.js as "the tie to go along with jQuery's tux, and Backbone.js' suspenders." Underscore.js was created by Jeremy Ashkenas, who is also known for Backbone.js and CoffeeScript. == History == First developed in 2009, Underscore has recently been overtaken by Lodash. - read more on Wikipedia