Filter Redundant Observable Emissions with RxJS distinct

RxJS^5.0.0

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Operator distinct() and its variants are an important type of Filtering operator. This lessons shows how they work and in what cases are they useful.

🚨 Since we are importing interval from RxJS, we don't need to preface our Observables with Rx.Observable. You can no longer .{operator}, you need to .pipe({operator}) instead.

Jon

~ 8 years ago

For people using TypeScript, you have have to import 'rxjs/add/operator/distinct'; Distinct was not included when importing 'rxjs/Rx'; and my build was erroring out.

Mike

~ 8 years ago

var result = foo.distinct((x,y) => x.toLowerCase() === y.toLowerCase());

gives: "error: TypeError: y is undefined"

Should be:

var result = foo.distinct((x) => x.toLowerCase());

André Staltz(instructor)

~ 8 years ago

Hi Mike. That's correct. We should update the lesson to use a 'keySelector' function, not a 'compare' function.