function newClosure(someNum, someRef) { // Local variables that end up within closure var num = someNum; var anArray = [1,2,3]; var ref = someRef; return function(x) { num += x; anArray.push(num); console.log('num: ' + num + '\nanArray ' + anArray.toString() + '\nref.someVar ' + ref.someVar); } } obj = {someVar: 4}; fn1 = newClosure(4, obj); fn2 = newClosure(5, obj); fn1(1); fn2(1); obj.someVar++; fn1(2); fn2(2);