Get value of first object property

var value = obj[Object.keys(obj)[0]];

Object.keys is included in javascript 1.8.5. Please check the compatibility here http://kangax.github.io/es5-compat-table/#Object.keys

Edit:

This is also defined in javascript 1.8.5 only.

var value = obj[Object.getOwnPropertyNames(obj)[0]];

Reference:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_Objects?redirectlocale=en-US&redirectslug=JavaScript%2FGuide%2FWorking_with_Objects#Enumerating_all_properties_of_an_object