Example 1: Some values false
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// RxJS v6+import { every } from 'rxjs/operators';import { of } from 'rxjs';//emit 5 valuesconst source = of(1, 2, 3, 4, 5);const example = source.pipe(//is every value even?every(val => val % 2 === 0));//output: falseconst subscribe = example.subscribe(val => console.log(val));
Example 2: All values true
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// RxJS v6+import { every } from 'rxjs/operators';import { of } from 'rxjs';//emit 5 valuesconst allEvens = of(2, 4, 6, 8, 10);const example = allEvens.pipe(//is every value even?every(val => val % 2 === 0));//output: trueconst subscribe = example.subscribe(val => console.log(val));
Example 3: Values arriving over time and completing stream prematurely due to every returning false
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// RxJS v6+console.clear();import { concat, of } from 'rxjs';import { every, delay, tap } from 'rxjs/operators';const log = console.log;const returnCode = request => (Number.isInteger(request) ? 200 : 400);const fakeRequest = request =>of({ code: returnCode(request) }).pipe(tap(_ => log(request)),delay(1000));const apiCalls$ = concat(fakeRequest(1),fakeRequest('invalid payload'),fakeRequest(2) //this won't execute as every will return false for previous line).pipe(every(e => e.code === 200),tap(e => log(`all request successful: ${e}`)));apiCalls$.subscribe();
every 📰 - Official docs
📁 Source Code: https://github.com/ReactiveX/rxjs/blob/master/src/internal/operators/every.ts