contains.md

Rx.Observable.prototype.contains(value, [comparer])

Ⓢ

Determines whether an observable sequence contains a specified element with an optional equality comparer.

Arguments

1. value (Any): The value to locate in the source sequence.
2. [comparer] (Function): An equality comparer function to compare elements.

Returns

(Observable): An observable sequence containing a single element determining whether the source sequence contains an element that has the specified value.

Example

/* Without a comparer */
var source = Rx.Observable.return(42)
    .contains(42);
    
var subscription = source.subscribe(
    function (x) {
        console.log('Next: ' + x.toString());
    },
    function (err) {
        console.log('Error: ' + err);   
    },
    function () {
        console.log('Completed');   
    });

// => Next: true
// => Completed 

/* With a comparer */
var source = Rx.Observable.return({ value: 42 })
    .contains(
        { value: 42}, 
        function (x, y) { return x.value === y.value; }
    );
    
var subscription = source.subscribe(
    function (x) {
        console.log('Next: ' + x.toString());
    },
    function (err) {
        console.log('Error: ' + err);   
    },
    function () {
        console.log('Completed');   
    });

// => Next: true
// => Completed 

Location

File:

• /src/core/linq/observable/contains.js

Dist:

• rx.all.js
• rx.all.compat.js
• rx.aggregates.js

Prerequisites:

• rx.js | rx.compat.js | rx.lite.js | rx.lite.compat.js

NPM Packages:

• rx

NuGet Packages:

• RxJS-All
• RxJS-Aggregates

Unit Tests:

• /tests/observable/contains.js