how to use the behaviorsubject function from the rxjs library in javascript

To use the BehaviorSubject function from the RxJS library in JavaScript, you need to first install RxJS in your project. You can do this using npm by running the following command:

index.tsx
npm install rxjs
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Once you have installed RxJS, you can import the BehaviorSubject class from the library like this:

index.tsx
import { BehaviorSubject } from 'rxjs';
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You can then create a new BehaviorSubject object by passing it an initial value as an argument:

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const subject = new BehaviorSubject(0);
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You can subscribe to the subject like this:

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subject.subscribe({
  next: (value) => console.log(`Current value: ${value}`)
});
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You can emit new values to the subject using its next method:

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subject.next(1); // logs "Current value: 1"
subject.next(2); // logs "Current value: 2"
subject.next(3); // logs "Current value: 3"
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The BehaviorSubject will immediately emit the current value to any new subscribers, as well as any subsequent values that are emitted to it.