//emit array as a sequence

const source = Rx.Observable.from([1,2,3,4,5]);

//demonstrating the difference between let and other operators

const test = source

  .map(val => val + 1)

  /*

    this would fail, let behaves differently than most operators

    val in this case is an observable

  */

  //.let(val => val + 2)

  .subscribe(val => console.log('VALUE FROM ARRAY: ', val));

​

const subscribe = source

  .map(val => val + 1)

  //'let' me have the entire observable

  .let(obs => obs.map(val => val + 2))

  //output: 4,5,6,7

  .subscribe(val => console.log('VALUE FROM ARRAY WITH let: ', val));