Introduction to Reactive Programming

React is not reactive (spoiler: not really), but Vue, Svelte and Angular are. But why? In the days of jQuery, when a program received data, it had to know all the places where that data was involved in order to update it. Now the frameworks let you just update the data, and they'll do the mapping themselves. This is one of the principles of reactivity - dependency inversion. The mapping follows the change in the data to do something itself. In React this does not happen, but still it is better than it was - now we do not need to update manually in all places, the framework will do it for us. The talk will not be about frameworks, although we will talk about them, too, but more about the fundamental things.