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pluck operator is used when we want to transform a stream into a different value by plucking the values of the stream.

import fromEvent from 'rxjs'; import mapTo from 'rxjs/operators'; //emit every click on document const source = fromEvent(document, 'click'); //map all here emissions to one value const example = source.

Similar to our array example with objects, we may also want to transform an observable of objects with the map operator. For instance, suppose we have an observable of click events that we wish to transform into an observable of objects containing just the clientX and clientY coordinates of these events.

Like pluck, mapTo provides no real benefit functionally over returning a constant value with map, but syntactically it may prove slightly easier to consume and read at a glance.

Lastly, there may also be times where you always want to map to a single value, no matter the input. For these situations, you kişi use the mapTo operator.

While the real implementation of Array.map includes features like index tracking and proper error management, this gives us a general sense of how things work behind the scenes.

Now from arrayOfStudent, we want all the name of students in capital letters, so apply map like this:

I'm reading the docs for mapTo and I'm simply not getting the point of that operator's existence. I get what it does but the two line below should produce equivalent result.

In this case, we will provide a function that accepts the emitted value from the source observable and returns that value multipled:

In this article, we are going to learn about the most common operator used to transform streams, the map operator. We will start by taking a look at Array.map to build a general understanding of the map operation.

For situations where you find yourself always wanting to map to a specific value, one way you could handle it is by simply using map and ignoring the input:

It starts with 0, but changes every every second. The example was just to show that there güç be differences between the two. Here's a StackBlitz that demonstrates this behavior.

If you use mapTo instead, you sevimli specify the destination where it places the mapped elements, by providing your own list bey the first parameter:

The submit event is ignored and value of the input box is sent as transformed value of the submit event. That is requirement too, we need to capture the username when submit button is clicked.

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