Compare performance as well as memory consumed of 3 JS Design Patterns: Factory, Constructor and Prototype

Produce a deep copy of a Javascript object where nested objects are not simply references to the originals.

Compares performance on the same task using Lodash vs two styles of Ramda vs two styles of "native" Javascript. In all cases the task is pulling "counter" property from each item in an array, filtering out odd items, squaring them, then returning those squared values that have less than two digits.

JS v JQ Test

JS v JQ

Is head() needed only to check length !== 0 ? P.s. Empty testcase for [0] is useless because it won't crash on trying to get nonexistent element