Question

Does anyone know what this code does? It is written in Javascript.

var RocknCoder = RocknCoder || {}; 

Answer 1

Short for:

if (!RocknCoder) var RocknCoder = {};

{} is an object initializer. Try verbalizing it and it makes more sense:

set variable RocknCoder equal to RocknCoder or {}

I believe that using the short form is better than the if simply because it blocks a ReferenceError from occurring on the if condition if the variable is not already declared in scope. var on the declaration may obviate that with hoisting, though.