Observable next method usage

console.clear();

var source = Rx.Observable.create(observer => {
  Rx.Observable.range(0,5).subscribe(
    data => { 
      console.log(data)
      if(data > 2) {
        // conveys to the subscriber of source
        // that values has changed
        observer.next("greater than 2");
      }
    }
  )
})

source.subscribe(
  data => console.log(data)
)