Responsive programming
define
Reactive programming is essentially a response to a flow of data or some kind of change, but when that change happens is unknown, so it is handled in an asynchronous, call-back manner.
example
It is easier to understand in combination with actual life. For example, people order food on the APP and then go to do something else, like work or listening to music or watching movies, instead of waiting for food all the time. Call asynchronously without blocking. Wait until the food arrives downstairs or at the door, the delivery boy will call you a signal, tell you the food arrived, you come down to pick up the food. Sometimes the delivery guy just drops it off at the front desk or in the box and leaves. Signal callback The whole process is done asynchronously. In this way, the user and the delivery boy do not have to wait all the time, which is relatively high efficiency.