reactive-programming

I've been looking to understand those 3: Subject , Behavior subject and Replay subject . I would like to use them and know when and why, what are the benefits of using them and although I've read the documentation, watched tutorials and searched google I've failed to make any sense of this. So what are their purpose? A real-world case would be most appreciated it does not have to even code. I would prefer a clean explanation not just "a+b => c you are subscribed to ...." Thank you It really comes down to behavior and semantics. With a Subject - a subscriber will only get published values that

The rxjava doc definition of switchmap is rather vague and it links to the same page as flatmap. What is the difference between the two operators? dwursteisen According to the documentation ( http://reactivex.io/documentation/operators/flatmap.html ) the switchMap is like the flatMap , but it will only emit items from the new observable until a new event is emitted from the source observable. The marble diagram shows it well. Notice the difference in the diagrams: In switchMap the second original emission ( green marble ) does not emit its second mapped emission ( green square ), since the

I'm learning RxJS and Angular 2. Let's say I have a promise chain with multiple async function calls which depend on the previous one's result which looks like: var promiseChain = new Promise((resolve, reject) => { setTimeout(() => { resolve(1); }, 1000); }).then((result) => { console.log(result); return new Promise((resolve, reject) => { setTimeout(() => { resolve(result + 2); }, 1000); }); }).then((result) => { console.log(result); return new Promise((resolve, reject) => { setTimeout(() => { resolve(result + 3); }, 1000); }); }); promiseChain.then((finalResult) => { console.log(finalResult);

Can someone give a clear definition together with a simple example that explains what is a "callback hell" for someone who does not know JavaScript and node.js ? When (in what kind of settings) does the "callback hell problem" occur? Why does it occur? Is "callback hell" always related to asynchronous computations? Or can "callback hell" occur also in a single threaded application? I took the Reactive Course at Coursera and Erik Meijer said in one of his lectures that RX solves the problem of "callback hell". I asked what is a "callback hell" on the Coursera forum but I got no clear answer.