Node.js Object object has no method 'hasOwnProperty'

Question

Not sure why hasOwnProperty() seems to be missing from my object...

I'm getting data from an http post in expressjs3, like this:

someControllerFunction: function(req, res){             var data = req.body.loc; ... } 

However if I do:

data.hasOwnProperty('test');  

I get:

Object object has no method 'hasOwnProperty'  

Perhaps I'm missing something obvious, but what?

(Node 10.5, Express 3.2.1)

Answer 1

The object may not have Object.prototype as its prototype.

This is the case if the object was created with...

var data = Object.create(null); 

You could use...

Object.prototype.hasOwnProperty.call(data, 'test'); 

...to test if the property exists.