Describe the JS module design pattern

JavaScript modules are the most prevalently used design patterns for keeping particular pieces of code independent of other components. This provides loose coupling to support well-structured code.

Modules should be Immediately-Invoked-Function-Expressions (IIFE) to allow for private scopes – that is, a closure that protect variables and methods (however, it will return an object instead of a function). This is what it looks like:

(function() {
    // declare private variables and/or functions
    return {
      // declare public variables and/or functions
    }
})();

Here we instantiate the private variables and/or functions before returning our object that we want to return. Code outside of our closure is unable to access these private variables since it is not in the same scope.