javascript / intermediate
Snippet
Parallel Processing with mergeMap
Unlike switchMap, mergeMap does not cancel previous requests. It handles multiple inner Observables concurrently, making it ideal for fire-and-forget actions or parallel data fetching where order doesn't matter.
snippet.js
javascript
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this.userIds$.pipe(mergeMap(id => this.userService.getDetails(id))).subscribe(userDetails => {this.allUsers.push(userDetails);});
angular
Breakdown
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mergeMap(id => ...)
Maps each ID to an HTTP request and executes them all in parallel.
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subscribe(...)
Receives results as they arrive, regardless of the order they were sent.