//only output distinct values, based on the last emitted value

const myArrayWithDuplicatesInARow = Rx.Observable

  .from([1,1,2,2,3,1,2,3]);

const distinctSub = myArrayWithDuplicatesInARow

    .distinctUntilChanged()

    //output: 1,2,3,1,2,3

    .subscribe(val => console.log('DISTINCT SUB:', val));

const nonDistinctSub = myArrayWithDuplicatesInARow

    //output: 1,1,2,2,3,1,2,3

    .subscribe(val => console.log('NON DISTINCT SUB:', val));