This post examines four ways in which values can be categorized in JavaScript: via the hidden property [[Class]], via the typeof operator, via the instanceof operator and via the function Array.isArray(). We’ll also look at the prototype objects of built-in constructors, which produce unexpected categorization results.
read more.......http://www.2ality.com/2013/01/categorizing-values.html
[This post is a copy of my Adobe Developer Connection article, I’m publishing it here for archival purposes.]