How to create deep object with dynamic name in Javascript?

How does the following javascript code create a safe reference to the underscore object?

• I was going through the annotated source code of underscore.js when I saw this snippet of code: var _ = function(obj) { if (obj instanceof _) return obj; if (!(this instanceof _)) return new _(obj); this._wrapped = obj; }; The annotation to this section reads "Create a safe reference to the Underscore object for use below." But how does this work? I'm new to javascript, a line by line explanation would be great. Thanks! via http://underscorejs.org/docs/underscore.html#section-9

• Answer:

  By the code you've posted what i understand is that it's just making sure if the obj being passed to it is of type _. If not they are converting it into an underscore object. The primary purpose of which is to ascertain that henceforth the variable is of this type.