Object.observe()

observe.js

var myObject = { name : 'flipjs' }

console.log('Start observing...')

Object.observe(myObject, function(changes) {
  changes.forEach(function(change) {
    console.log(change.name
              + " was "
              + change.type
              + " and is now "
              + change.object[change.name])
  })
})

console.log(myObject)

window.setTimeout(function(){myObject.name = 'philip'}, 1000)

window.setTimeout(function(){myObject.name = 'foobar'}, 1000)

window.setTimeout(function(){myObject.age = 42}, 1000)

window.setTimeout(function(){myObject.age = 24}, 1000)

console.log('End program.')