Build Reactive Websites with RxJS: Master Observables and Wrangle/

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The Two Merges

The Two Merges

Let's see how we can use merge as a constructor as well as an operator.

We'll cover the following...

The two merges

In the below example, merge is used as a constructor (a way to create a new observable).

In cases where everything starts at the same time (like the loading bar), merge used as a constructor is simpler than the operator form.

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merge(...requests)
.subscribe(
    val => drawToPage(val),
    err => alert(err)
);

However, it’s also an operator:

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let obsOne$ = interval(1000);
let obsTwo$ = interval(1500);
// Piping through the merge operator
obsOne$
.pipe(
  merge(obsTwo$)
)
.subscribe(console.log);
// Is the same as using the merge constructor
merge(obsOne$, obsTwo$)
.subscribe(console.log);

merge as “operator”

The operator form of merge comes in handy when you’re in the middle of an observable chain and want to add in more data. ...