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

( jsBin |
jsFiddle )

import { every } from 'rxjs/operators';
import { of } from 'rxjs/observable/of';
//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

( jsBin |
jsFiddle )

import { every } from 'rxjs/operators';
import { of } from 'rxjs/observable/of';
//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));

Additional Resources

• every
  - Official docs

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