map operator

map-operator.js

const { interval } = Rx;
const { map, take } = RxOperators;

// The input observable will emit the values 1, 2, 3 
// in 1 second intervals
function inputObservable() {
  const returnValues = [1, 2, 3];
  return interval(1000)
    .pipe(
    	take(returnValues.length),
    	map(val => returnValues[val])
  	);
}

// =====================================
// Don't worry about anything above this
//
// Just know that the input Observable
// returns the values 1, 2, 3
// =====================================

inputObservable().pipe(
  
  // 10 * 1 = 10
  // 10 * 2 = 20
  // 10 * 3 = 30
  map(x => 10 * x)
)