Subscribe can take three params:

subscribe(        (x)=> console.log(x),        err=> console.log(err),        ()=> console.log('complete')    );

 

If we want to stop the progame at some condition, so we need to notify complete function, which is the third param in subscribe.

Observable.combineLatest(    timer$,    input$,    (timer, input)=> ({count: timer.count, text: input}))    .takeWhile((data)=> data.count <= 3)    .filter((data)=> data.count === parseInt(data.text))    .subscribe(        (x)=> console.log(x),        err=> console.log(err),        ()=> console.log('complete')    );

We can use takeWhile() function to end the program, so after the count = 3, "complete" will logout