Checking for Titanium API objects

index.js

var jsObject = {
	foo: 'bar'
};

var tiObject = Ti.UI.create2DMatrix();

function isJsObject(obj) {
	return  typeof obj.__proto__ !== 'undefined';
}

console.log('jsObject: ' + (isJsObject(jsObject) ? 'yes' : 'no'));
console.log('tiObject: ' + (isJsObject(tiObject) ? 'yes' : 'no'));

Looks like that as an expression (or part of one) it returns undefined, but when passed around (assignment, or function invocation) is null.

I feel stupid. _proto__ with one _…

function isJSObject(o) { return !!(o && o.__proto__ !== undefined); };

works flawlessy…