every

signature: every(predicate: function, thisArg: any): Observable

If all values pass predicate before completion emit true, else false.

Examples

Example 1: Some values false

( Stackblitz | jsBin | jsFiddle )

// RxJS v6+ import { every } from 'rxjs/operators'; import { of } from 'rxjs';  //emit 5 values const source = of(1, 2, 3, 4, 5); const example = source.pipe(  //is every value even?  every(val => val % 2 === 0) ); //output: false const subscribe = example.subscribe(val => console.log(val));

Example 2: All values true

( Stackblitz | jsBin | jsFiddle )

// RxJS v6+ import { every } from 'rxjs/operators'; import { of } from 'rxjs';  //emit 5 values const allEvens = of(2, 4, 6, 8, 10); const example = allEvens.pipe(  //is every value even?  every(val => val % 2 === 0) ); //output: true const subscribe = example.subscribe(val => console.log(val));

Example 3: Values arriving over time and completing stream prematurely due to every returning false

( Stackblitz )

// 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();

Additional Resources

• every 📰 - Official docs

---

📁 Source Code: https://github.com/ReactiveX/rxjs/blob/master/packages/rxjs/src/internal/operators/every.ts