every.md

every

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

Description

TL;DR: Does every emitted value pass condition?

The every operator accepts a predicate function, testing every emission from the source against this function. If the result of the predicate for each emission is truthy the operator will return true, if not, it will return false. Note that the every operator will only emit a value when the source completes.

Examples

Example 1: Some values false

( jsBin | jsFiddle )

//emit 5 values
const source = Rx.Observable.of(1,2,3,4,5);
const example = source
  //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 )

//emit 5 values
const allEvens = Rx.Observable.of(2,4,6,8,10);
const example = allEvens
  //is every value even?
  .every(val => val % 2 === 0);
//output: true
const subscribe = example.subscribe(val => console.log(val));

Additional Resources

• every 📰 - Official docs

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