Javascript has array_map called Array.prototype.map(), it has an array_merge method called Array.prototype.concat(), array_reject can be achieved using Array.prototype.filter() and so on. These functions are a poor reimplementation of some native features.
Why not actually push a .js file instead of just examples in a readme?<p>Or, I guess the modern method would be why not publish every line of every function as a separate NPM package?
Well, there's always this: <a href="http://locutus.io/php/" rel="nofollow">http://locutus.io/php/</a><p>PHP functions written in Javascript. Been around for quite a while, actually.