console.clear()

var source = Rx.Observable.interval(1000)

             .do(x => console.log('send: ' + x))

             .multicast(new Rx.Subject())

             .refCount();

​

var observerA = {

    next: value => console.log('A next: ' + value),

    error: error => console.log('A error: ' + error),

    complete: () => console.log('A complete!')

}

​

var observerB = {

    next: value => console.log('B next: ' + value),

    error: error => console.log('B error: ' + error),

    complete: () => console.log('B complete!')

}

​

var subscriptionA = source.subscribe(observerA);

// 訂閱數 0 => 1

​

var subscriptionB;

setTimeout(() => {

    subscriptionB = source.subscribe(observerB);

    // 訂閱數 0 => 2

}, 1000);