concat.md

Rx.Observable.concat(...args)

Ⓢ

Concatenates all of the specified observable sequences, as long as the previous observable sequence terminated successfully.

Arguments

1. args (Array | arguments): Observable sequences or Promises to concatenate.

Returns

(Observable): An observable sequence that contains the elements of each given sequence, in sequential order.

Example

/* Using Observable sequences */
var source1 = Rx.Observable.return(42);
var source2 = Rx.Observable.return(56);

var source = Rx.Observable.concat(source1, source2);

var subscription = source.subscribe(
    function (x) {
        console.log('Next: ' + x);
    },
    function (err) {
        console.log('Error: ' + err);
    },
    function () {
        console.log('Completed');
    });

// => Next: 42
// => Next: 56
// => Completed

/* Using Promises and Observable sequences */
var source1 = Rx.Observable.return(42);
var source2 = RSVP.Promise.resolve(56);

var source = Rx.Observable.concat(source1, source2);

var subscription = source.subscribe(
    function (x) {
        console.log('Next: ' + x);
    },
    function (err) {
        console.log('Error: ' + err);
    },
    function () {
        console.log('Completed');
    });

// => Next: 42
// => Next: 56
// => Completed

Location

File:

• /src/core/perf/operators/concat.js

Dist:

• rx.all.js
• rx.all.compat.js
• rx.js
• rx.compat.js
• rx.lite.js
• rx.lite.compat.js

Prerequisites:

• None

NPM Packages:

• rx

NuGet Packages:

• RxJS-Complete
• RxJS-Main
• RxJS-Lite

Unit Tests:

• /tests/observable/concat.js