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'));