In JavaScript, there is no such thing as a private variable.  In order to achieve encapsulation and information hiding in JavaScript, I can wrap a variable inside a function closure, like so:var counter = (function() {        var i = 0;    var fn = {};    fn.increment = function() { i++; };    fn.get = function() { return i; };    return fn;{)();    counter.increment();counter.increment();alert(counter.get()); // alerts '2'Since I don't call i a private variable in JavaScript, what do I call it?
What is the proper jargon to refer to a variable wrapped inside a function closure?
javascript;closures;jargon
According to wikipedia they're called upvalues.A closure allows a function to access variables outside its immediate  lexical scope. An upvalue is a free variable that has been bound  (closed over) with a closure. The closure is said to close over its  upvalues.Although it's probably better to wrongly call them private variables so people will understand what you mean.